Agreed. Either Odysee's class F or the Verity (Picard and Raffi's old ship) would've been great. I don't mind seeing the E for nostalgic reasons.
But hopefully not the Squadron doesn't consist of Constitution or Miranda-class ships. Seeing them during the Dominion War was OK (a tribute to TOS plus Starfleet needed all the ships it could get in a major crisis). But seeing them atilll in action some 25 years later could've leave some to wonder "Hmmm, is Starfleet got no money or it's way overstretched that these old birds are still in operation more than 130 years after they were launched....
It would be a mix of ship classes I would think.
Just imagine if someone rolls up in a Discoprise, the screams that will echo through this forum, I doubt we will see any legacy ship classes like the Reliant or Constitution though, we could perhaps see an Excelsior as some must have survived the Dominion War but that is about it.
A lot depends on money, they can use existing ships from TNG/DS9/VOY easily enough without breaking the bank which is why it will probably be the Enterprise E if we see any Enterprise at all.
With maybe a Galaxy, Nebula, Akira or Steamrunners, maybe even a Defiant class or an Intrepid.
I would love to see any Odyssey class, sending the USS Verity would be a nice gesture by Clancy.
Fact is we may not see any ships at all with just a cliff hanger until next season.
It really depends on what the show runners want to achieve with the final two episodes, do they want it to end positively with a last minute save by Starfleet or allied Romulan ships (Laris/Zhaban) or negatively by showing us that the big bad has arrived and that the Zhat Vash were right.
It could go in any number of directions really.