I know Dave has said he's done with the role after this. Which is fine, the MCU is fine without Drax. But I hope 2-3 members are able to keep going in the MCU. Not in the Guardians but just popping up in other things, whether it's Rocket (whose death is SO telegraphed at this point that I'm also thinking he'll be fine....unless they're trying to get me to think that! DAMN THEM!) or Quill or Nebula, I'd like some of this to keep going in other ways.
Given that Rocket and Groot are voice-over roles, I can see them coming back if they survive Volume 3. Peter probably will as well since he has virtually no make-up to put on like Gamora, Drax, or Nebula, all three of whom I could see bowing out of the franchise after Volume 3, assuming their characters don't die in the film. I'd also love to see Cosmo return, since it seems we've barely gotten to know them up til now. Give me a Cosmo Disney+ special or a series of shorts, maybe with Rocket and Groot too!
It's hard to say, though, if any of them WILL return given how close they've all been to Gunn and how these characters have been babies to him for the last near-decade. I guess it's up to the story Feige wants to tell with them, and if the actors would want to return without Gunn at the helm. Granted, they appeared in Infinity War, Endgame, and Love & Thunder, (just as many times without Gunn as with, counting the Holiday Special), so it's not like they COULDN'T be in a film/special/show without Gunn, but I'd say it's less likely.
It would also be nice for Volume 3 to be a complete and cohesive ending to the trilogy, which seems to be a difficult thing to do in the MCU, since characters like Iron Man, Captain America, and Thor all had to continue past their third films given their connections to the Avengers and the broader MCU. With the Guardians, they could phase them out and their absence might not affect any of the future story-telling they have in mind, so this could be the first completely closed trilogy in the MCU. That would be a benefit or a detriment. I guess we'll find out in 3 months!
-Marc.