The server reflection service has a v1:
https://github.com/grpc/grpc/blob/master/src/proto/grpc/reflection/v1/reflection.proto

But this repo still only uses the v1alpha version.

Ideally, the implementation in the reflection sub-package would register implementations for both (or at least accept an option to do so). That would support a transition to the v1 API while still supporting clients that continue to use the v1alpha version.