I agree with others who say that GSP-Conor is a squash match. However, I do think it seems very plausible that they'd make that fight. They were trying to set that fight up the first time, before Nate ruined their plans, so it makes sense that they'd go that rout again. Perhaps that's why they insisted that this fight be at 170.
I'd prefer GSP take on more interesting challenges (fighting a FW isn't all that interesting). And he's already cemented himself as WW GOAT, so there's no need to go back. I'd rather he go to LW (since he said it wouldn't be a problem) or fight at MW. Even a fight with Hendricks could be interesting, despite his fall from contention.