Both Hammond and May have 'other jobs' on the BBC and do them quite well. So would they walk away from the BBC in solidarity with JC? I don't see that happening without a serious Plan.
JC might be holding the Beeb to ransom - more money to re-sign. I think they should call his bluff and put TG to bed for a while, But I do think they should screen the remainder of this series. Having presumably recorded most of it already and so incurred the costs, it is petty in the extreme to refuse to screen those episodes. Even if JC is excluded from the hangar scenes, or better still, is sitting there with gaffer tape round his orifice.