Inferno is not a successor. For example you can have Golang for Plan 9 but doesn’t make much sense on Inferno. You would even run Inferno on Plan 9 on some scenarios. I suspect most people who know about Plan 9 also know about Inferno, but it’s just a different thing, does not supersede it in general.

Plan 9 => Inferno

Alef => Limbo => Go.

Being able to target Plan 9 with Go doesn't make sense, that isn't how historical evolution works.

I suspect you would have to port Go to run on Dis, the VM. C is for the OS. It’s a different design, without mmu. Plan 9 is still a classic OS with hardware isolation