My suspicion is that if heavy regulation were to be put on it and all the corporate entities involved backed off, there are enough motivated and capable individuals that have home labs that would continue to work on it in private. It might be more difficult and slower, but distributed training protocols/methods (or advancements in them) might make it possible to pool a few thousand (or tens of thousand) high end consumer GPUs to continue to push the envelope.
My gut feel is that just as there are certain books, games and movies that get banned and become illegal to posses, there are probably (or potentially) going to be certain models that you're not allowed to be in possession due to what they can do. So... grab a copy of them while you can.