The decision at the moment is that while there may be backwards-incompatible language changes, referred to with the go2 label, Go is not planning to ever releas

The decision at the moment is that while there may be backwards-incompatible language changes, referred to with the go2 label, Go is not planning to ever release a backwards-incompatible compiler. That means code written today will always be able to be imported by and linked against future Go programs, but there may be future language features you can't use without explicitly opting in. The go module system also has a way to declare language version, although it doesn't do anything right now.