https://godbolt.org/z/cYYaPPGor
Consider the original code (this is how I want it to look)
[[deprecated]]
void f() = delete;
With
BreakAfterAttributes: Always
BasedOnStyle: WebKit
I get
[[deprecated]]
void f()
= delete;
I don't why it breaks the = delete onto the next line. This doesn't happen with BreakAfterAttributes: Never, so it seems more like a bug than intentional formatting.