diff --git a/src/coreclr/inc/predeftlsslot.h b/src/coreclr/inc/predeftlsslot.h
index 9ac1402589c5c..b84d112558a2a 100644
--- a/src/coreclr/inc/predeftlsslot.h
+++ b/src/coreclr/inc/predeftlsslot.h
@@ -22,17 +22,17 @@ enum PredefinedTlsSlots
 enum TlsThreadTypeFlag // flag used for thread type in Tls data
 {
     ThreadType_GC                       = 0x00000001,
-    ThreadType_Timer                    = 0x00000002,
-    ThreadType_Gate                     = 0x00000004,
+    // ThreadType_Timer                    = 0x00000002,
+    // ThreadType_Gate                     = 0x00000004,
     ThreadType_DbgHelper                = 0x00000008,
     ThreadType_Shutdown                 = 0x00000010,
     ThreadType_DynamicSuspendEE         = 0x00000020,
     ThreadType_Finalizer                = 0x00000040,
-    ThreadType_ADUnloadHelper           = 0x00000200,
-    ThreadType_ShutdownHelper           = 0x00000400,
-    ThreadType_Threadpool_IOCompletion  = 0x00000800,
-    ThreadType_Threadpool_Worker        = 0x00001000,
-    ThreadType_Wait                     = 0x00002000,
+    // ThreadType_ADUnloadHelper           = 0x00000200,
+    // ThreadType_ShutdownHelper           = 0x00000400,
+    // ThreadType_Threadpool_IOCompletion  = 0x00000800,
+    // ThreadType_Threadpool_Worker        = 0x00001000,
+    // ThreadType_Wait                     = 0x00002000,
     ThreadType_ProfAPI_Attach           = 0x00004000,
     ThreadType_ProfAPI_Detach           = 0x00008000,
     ThreadType_ETWRundownThread         = 0x00010000,
diff --git a/src/coreclr/inc/utilcode.h b/src/coreclr/inc/utilcode.h
index 192bdc5d0d597..5fef649852658 100644
--- a/src/coreclr/inc/utilcode.h
+++ b/src/coreclr/inc/utilcode.h
@@ -3431,16 +3431,6 @@ inline BOOL IsGCSpecialThread ()
     return !!(t_ThreadType & ThreadType_GC);
 }
 
-// check if current thread is a Gate thread
-inline BOOL IsGateSpecialThread ()
-{
-    STATIC_CONTRACT_NOTHROW;
-    STATIC_CONTRACT_GC_NOTRIGGER;
-    STATIC_CONTRACT_MODE_ANY;
-
-    return !!(t_ThreadType & ThreadType_Gate);
-}
-
 // check if current thread is a debugger helper thread
 inline BOOL IsDbgHelperSpecialThread ()
 {
@@ -3481,33 +3471,6 @@ inline BOOL IsShutdownSpecialThread ()
     return !!(t_ThreadType & ThreadType_Shutdown);
 }
 
-inline BOOL IsThreadPoolIOCompletionSpecialThread ()
-{
-    STATIC_CONTRACT_NOTHROW;
-    STATIC_CONTRACT_GC_NOTRIGGER;
-    STATIC_CONTRACT_MODE_ANY;
-
-    return !!(t_ThreadType & ThreadType_Threadpool_IOCompletion);
-}
-
-inline BOOL IsThreadPoolWorkerSpecialThread ()
-{
-    STATIC_CONTRACT_NOTHROW;
-    STATIC_CONTRACT_GC_NOTRIGGER;
-    STATIC_CONTRACT_MODE_ANY;
-
-    return !!(t_ThreadType & ThreadType_Threadpool_Worker);
-}
-
-inline BOOL IsWaitSpecialThread ()
-{
-    STATIC_CONTRACT_NOTHROW;
-    STATIC_CONTRACT_GC_NOTRIGGER;
-    STATIC_CONTRACT_MODE_ANY;
-
-    return !!(t_ThreadType & ThreadType_Wait);
-}
-
 // check if current thread is a thread which is performing shutdown
 inline BOOL IsSuspendEEThread ()
 {
@@ -3527,15 +3490,6 @@ inline BOOL IsFinalizerThread ()
     return !!(t_ThreadType & ThreadType_Finalizer);
 }
 
-inline BOOL IsShutdownHelperThread ()
-{
-    STATIC_CONTRACT_NOTHROW;
-    STATIC_CONTRACT_GC_NOTRIGGER;
-    STATIC_CONTRACT_MODE_ANY;
-
-    return !!(t_ThreadType & ThreadType_ShutdownHelper);
-}
-
 inline BOOL IsProfilerAttachThread ()
 {
     STATIC_CONTRACT_NOTHROW;
diff --git a/src/coreclr/vm/threads.cpp b/src/coreclr/vm/threads.cpp
index 68e2d80935c40..5e88929ac7289 100644
--- a/src/coreclr/vm/threads.cpp
+++ b/src/coreclr/vm/threads.cpp
@@ -683,22 +683,6 @@ Thread* SetupThread()
         // thread spinning up.
         if (pThread)
         {
-            if (IsThreadPoolWorkerSpecialThread())
-            {
-                pThread->SetThreadState(Thread::TS_TPWorkerThread);
-                pThread->SetBackground(TRUE);
-            }
-            else if (IsThreadPoolIOCompletionSpecialThread())
-            {
-                pThread->SetThreadState(Thread::TS_CompletionPortThread);
-                pThread->SetBackground(TRUE);
-            }
-            else if (IsWaitSpecialThread())
-            {
-                pThread->SetThreadState(Thread::TS_TPWorkerThread);
-                pThread->SetBackground(TRUE);
-            }
-
             BOOL fStatus = pThread->HasStarted();
             ensurePreemptive.SuppressRelease();
             return fStatus ? pThread : NULL;
@@ -775,19 +759,6 @@ Thread* SetupThread()
 
     ensurePreemptive.SuppressRelease();
 
-    if (IsThreadPoolWorkerSpecialThread())
-    {
-        pThread->SetThreadState(Thread::TS_TPWorkerThread);
-    }
-    else if (IsThreadPoolIOCompletionSpecialThread())
-    {
-        pThread->SetThreadState(Thread::TS_CompletionPortThread);
-    }
-    else if (IsWaitSpecialThread())
-    {
-        pThread->SetThreadState(Thread::TS_TPWorkerThread);
-    }
-
 #ifdef FEATURE_EVENT_TRACE
     ETW::ThreadLog::FireThreadCreated(pThread);
 #endif // FEATURE_EVENT_TRACE
diff --git a/src/coreclr/vm/threads.h b/src/coreclr/vm/threads.h
index 1ae521b87d54b..656fc5fd44e68 100644
--- a/src/coreclr/vm/threads.h
+++ b/src/coreclr/vm/threads.h
@@ -644,7 +644,7 @@ class Thread
         TS_Interruptible          = 0x02000000,    // sitting in a Sleep(), Wait(), Join()
         TS_Interrupted            = 0x04000000,    // was awakened by an interrupt APC. !!! This can be moved to TSNC
 
-        TS_CompletionPortThread   = 0x08000000,    // Completion port thread
+        // unused
 
         TS_AbortInitiated         = 0x10000000,    // set when abort is begun
 
@@ -1882,7 +1882,7 @@ class Thread
     BOOL        IsThreadPoolThread()
     {
         LIMITED_METHOD_CONTRACT;
-        return m_State & (Thread::TS_TPWorkerThread | Thread::TS_CompletionPortThread);
+        return m_State & Thread::TS_TPWorkerThread;
     }
 
     void        SetIsThreadPoolThread()
diff --git a/src/coreclr/vm/util.cpp b/src/coreclr/vm/util.cpp
index d03ecb7326073..2065677ed810e 100644
--- a/src/coreclr/vm/util.cpp
+++ b/src/coreclr/vm/util.cpp
@@ -28,12 +28,7 @@ void ClrFlsSetThreadType(TlsThreadTypeFlag flag)
 
     // The historic location of ThreadType slot kept for compatibility with SOS
     // TODO: Introduce DAC API to make this hack unnecessary
-#if defined(_MSC_VER) && defined(HOST_X86)
-    // Workaround for https://developercommunity.visualstudio.com/content/problem/949233/tls-relative-fixup-overflow-tls-section-is-too-lar.html
-    gCurrentThreadInfo.m_EETlsData = (void**)(((size_t)&t_ThreadType ^ 1) - (4 * TlsIdx_ThreadType + 1));
-#else
     gCurrentThreadInfo.m_EETlsData = (void**)&t_ThreadType - TlsIdx_ThreadType;
-#endif
 }
 
 void ClrFlsClearThreadType(TlsThreadTypeFlag flag)