Update verbiage of changelog (#15177)

Author: JoshLove-msft

sdk/eventgrid/Azure.Messaging.EventGrid/CHANGELOG.md

@@ -3,7 +3,7 @@
 
 
 ## 4.0.0-beta.1 (2020-09-08)
-This is the first preview of the Azure Event Grid client library that follows the [.NET Azure SDK Design Guidelines](https://azure.github.io/azure-sdk/dotnet_introduction.html). This library is not a direct replacement for `Microsoft.Azure.EventGrid`, as code changes would be required to use the new library.
+This is the first preview of the Azure Event Grid client library that follows the [.NET Azure SDK Design Guidelines](https://azure.github.io/azure-sdk/dotnet_introduction.html). This library is not a drop-in replacement for `Microsoft.Azure.EventGrid`, as code changes would be required to use the new library.
 
 This package's [documentation](https://github.com/Azure/azure-sdk-for-net/blob/master/sdk/eventgrid/Azure.Messaging.EventGrid/README.md) and [samples](https://github.com/Azure/azure-sdk-for-net/blob/master/sdk/eventgrid/Azure.Messaging.EventGrid/samples/README.md) demonstrate the new API.
 ### Features: