Is this sometime through year end? I am not normally one to let resort construction influence my plans - I have a pretty high tolerance for that kind of stuff. But for me, I think with how relatively central/integral the lobby is for a Royal Palm Club stay, I'd have to think twice about GF right now. Or at least keep a really close eye on blog reports to know what's going on leading up to your trip. RPC tends to be so darn expensive, the possible negatives of any noise or visual nuisance would probably influence me, personally.
Also my personal bias, I think these boards and the "flagship resort" narrative associated with the Grand can sometimes overhype RPC more than is deserved. Is it a nice CL? For sure. The recent renovations were great and everything is nice/bright/clean. But on some level it's just a CL like everywhere else, CMs are sometimes helpful, sometimes not, the guest count is relatively high there so lounge conditions can be busy (although lots of room to spread out/find tables), the food options are directionally the same as everywhere else. Sorry to be a little negative - my brain is guilty of letting RPC get overhyped in my head, and when we leave we sometimes find ourselves questioning if it was really worth it.