That's one of the big reasons that Endgame wasn't a satisfying ending for me. Besides of course the emotional moments reconnecting with their families, I really wanted to see Starfleet's reaction to some of this stuff.
Hey we're back, don't mind the Borg on board, she's with us. Yes, that's our EMH. He's mobile now thanks to a future holoemitter. Oops, just let me disable the ablative armour on this ship we also got from the future. Oh and please don't arrest the Maquis guys. They're my first officer and chief engineer.
Yeah, I know they had some contact to Starfleet with that communications array, but it's not the same.