You see Oberon's influence on how ACME editor works, and later the OS dynamism enjoyed by Inferno and Limbo, that everyone usually forgets about.
Alef => Limbo => Go.
Being able to backport Go into Plan 9, doesn't make sense in this context, that isn't how historical evolution works.
Also even Inferno has the necessary C infrastructure to port Go, if someone hasn't done it already.