My thoughts on the mons:
I feel like I should be happy with the new reveals, since I've always been a fan of the more artificial ones. But Duraludon seems a lot more timid in that concept than all the ones from gen 5, let alone the on-theme UBs like Xurkitree. Maybe this isn't supposed to be an artifical-seeming mon, but then the lack of one is itself disappointing (If I recall correctly, honedge and klink were pretty early reveals for their respective gens, and I wasn't all that happy with how the archetype was pushed to the side in Alola). Fairy indifferent on slurpuff 2 (pun intended), and I'm hoping Rolycoly isn't the last we see of Steam Engine (either through another line or a differently-typed evolution, my desire for a true gen 8 artifice-mon may be a part of this). Maybe the teapot that is mentioned while I was typing this will fill my need.
On Gigantamax:
I'm not sure why they would put the restriction in place. With all the known users being gen 8 and the leak referencing NFEs, it casts doubt on the only real reason I can think of, wanting to restrict moves imported from earlier games (being untransferable and not exactly overpowered respectively. If it's correct that it is raid-locked, that's going to be a hot mess for competitive. I can already imagine the rage when you get two conflicting Synchonizers in a party (and I pray for those not using simulators that there exists an IV control for raids). It doesn't seem massive in VGC, where hazards aren't as big a deal and you might prefer the ability to win the weather/terrain war over the secondary effects (assuming it replaces the standard typed Max move), but I agree it likely outclasses normal Maxing in singles. Also, a giant cake with a barrier based on number of hits? Pokemon x SMRPG confirmed?