Not really. Think about it. Only to remove restrictions from a license do you need permission from the existing developers. To introduce extra restrictions you

Not really. Think about it. Only to remove restrictions from a license do you need permission from the existing developers. To introduce extra restrictions you don't need anyone's permission. If Linus chooses to accept a single patch that's GPLv3, the kernel is GPLv3 from that point forward. Linus has in fact done this to quite a bit of MIT licensed code. Of course it only applies to future versions, and you could conceivably make versions that have those patches removed.