From my personal experience I never had the feeling that Nintendo wanted to balance the game by reprinting "important" cards. Sure, all the staple trainers are reprinted, but that's not balance, that's keeping decks working. If they did however announce their opinion of what important cards are, there'd also be ban lists and way more erratas than there are now. I'm not saying that the game isn't balanced, at least it's more balanced than back when Magmortar and Plox ruled all, but Nintendo is better at creating balance by making new cards than by aftercare. So I don't think Unown G will be reprinted if GE goes out. All the arguments that "Claydol should stay" and stuff are in my opinion not relevant.
That being said, I agree with d master and also think that they won't rotate sets which will be inconvenient for them (aka they'll have to make more porygunz) and with the release of the promo Porygon Z, it's even more likely that the Porygons are there to stay. So I'll bet my money on GE-on. Makes sense because next year it will obviously be PT-on. And we'd lose 4 more sets instead of 7 at once. Sounds reasonable to me.