Is this worthy a submission of its own? It's in the bootstrap cycle - for 'just' an added keyring (which is a nice-to-have, agreed.. but bootstrapping for it?)

On it's own it wouldn't be worthwhile, I agree. But if you need to do a bootstrap for other reasons it would be nice to take this one (as there are no source changes it shouldn't affect anything). For the time being I haven't more binutils updates in the queue, which is why I submitted it anyway. So feel free to delay until you need to do a bootstrap.