Looks like the engine now creates a .suppressed file which will force you to include what you use instead of letting your headers make use of Core.h or Engine.h as a whole; so if you use classes from different modules you have to include those module’s headers now, simply adding Engine.h won’t work.
UUserDefinedEnums have changed; there’s no more TArray<FName> DisplayNames, it’s now a TMap<FName,FText> DisplayNamesMap.
If you do DisplayNamesMap.GenerateValueArray() you get the stored Enum names from there.