Urshifu is meant to come at about level 30 so I think level 30 birds you're (hypothetically) meant to catch wouldn't be too outlandish provided the DLC is meant to "start" at midgame. Coincidentally, around when you are required to go back through the wild area a second time!Honestly I expect it to be available after Leon. In this case they are probably going to be feeding you multiple legendary pokemon (exp if the Regis/Birds are part of the plot) and I think even GF would realize it's a bad idea to feed you level 30 legendaries halfway in the story (hello Latis).
Honestly this question is partially why I asked if there were any progress blockers with Armor. Letting you get the birds (& Urshifu) at midgame wouldn't be too bad, I think, but also the regi in short order? Plus *mhm* whatever else is in there.
oh for sure, this is why I think Calyrex is definitely going to be on par with the "get urshifu's g-max/fight mustard". The finale part of the DLC you can't do until you've beaten the game.Also, there's the fact Calyrex might have some connection with the "ancient heros" like the dogs, which would also want a plot that acts as continuation of the main one rather than "side story" like Kubfu's.