Yes (actually, it would only have to be a soft fork), but that would require serious coordination. Ethereum has done it before, so it's not literally impossible

Yes (actually, it would only have to be a soft fork), but that would require serious coordination. Ethereum has done it before, so it's not literally impossible, but it would require the whole of the Ethereum network to do it, not just the ENS people. If it did happen, it would raise serious questions about the nature of the decentralization of Ethereum, and how suitable it is as a deterministic platform to build stuff on. Then again, it already happened and nobody seemed to really care. If Ethereum is willing to fork over X, what's to say they're not willing to fork over Y? And the answer to this question is probably to do with "the big guys with the money at the top like X, but not Y". So much for decentralization.