I agree that breaking backwards compatibility from 3.81 to 3.82 was not a good idea. However, breaking compatibility from 3.x to 4.x is perfectly fine and won'

I agree that breaking backwards compatibility from 3.81 to 3.82 was not a good idea. However, breaking compatibility from 3.x to 4.x is perfectly fine and won't cause any surprisings. After all, that's what major version number are good for. (... at least in their original meaning, before various free software projects started some strange kind of race with their major version numbers)