No, we certainly can't expect sudden improvement when there already hasn't been actual improvement, even if the overall winning percentage is about the same [and indeed, this is the fifth-best Phillies team at the All-Star break in franchise history].
But they didn't actually "run it back." Now it's very clear that one aspect of the team greatly improved [both through a good addition and guys just getting better, even w/o Nola] while two others declined [due to not-good additions and guys just getting worse]. Defense is probably about the same.
The team this one most resembles is the 2011 Phillies. That club didn't need any relief pitchers. Did it actually need Hunter Pence? The result that year says no. I still wouldn't mind if this team could go get a Hunter Pence, but I'm not sure there's one to be gotten. I also still feel like the '23 and '24 teams never really made up for the loss of Hoskins and there's no one like him out there to be gotten either, unless you move Harper or Schwarber to OF.
My guess is after the deadline when Dombrowski gets a reliever and another Austin Hays, he will say something like, "our real trade deadline additions are a healthy Aaron Nola, a hot Bryce Harper and Andrew Painter."