See the doc I linked above: https://github.com/golang/proposal/blob/master/design/28221-go2-transitions.md https://github.com/golang/proposal/blob/master/design

See the doc I linked above: https://github.com/golang/proposal/blob/master/design/28221-go2-transitions.md https://github.com/golang/proposal/blob/master/design/28221-... Probably not. We can add things and we can opt-in remove things (e.g. user says they want v1.14 of language gets them new language features and removes some language features), but we can't change the semantics of existing programs. That is, if a program compiles with two different language versions, that program should mean the same in both versions.