It appears that there is an exception that will allow them to manufacture them in state for out of state sale.
Magpul doesn't care. If it passes, they're leaving.
As for how moving will affect things, from what they've said it looks like they're still figuring that out. They're putting things into place so as little interruption as possible happens but I can't imagine that there won't be some hiccup.
I also wonder if some of their suppliers won't move with them. If they don't the disruption could be longer lived until new suppliers are lined up.