So my ideas is to extend the warning message with more information about what the user should do to fix the issue. It could look like this:
I think this idea is better than e.g. still listing the old functions in the help file which can lead to confusion. Although you could create an extra "Deprecated Functions" topic about it which simply has a list with the same information as above ("CreateGadgetList() -> Remove" etc.). It would help enormously for quick and easy lookups instead of always having to look at the changelog.Warning! Deprecated function used [Line 1234]: CreateGadgetList()
Solution: Remove the function
Warning! Deprecated function used [Line 4321]: CountList()
Solution: Replace it by ListSize()