Could we see Yondu return in Guardians of the Galaxy Vol. 3? Not if James Gunn has any say on the matter... and, thankfully, he does.
Michael Rooker's fan-favorite Ravager was pretty definitively killed off (it doesn't get much more final than cremation) when he sacrificed himself to save his adoptive son Peter Quill (Chris Pratt) at the end of Vol. 2, but there still seems to be a lot of speculation that he'll somehow return to the MCU down the line.
To be fair, it's not exactly unheard of for Marvel Studios to bring a character back from the dead, but Gunn is adamant that Yondu will not be resurrected "as long as I'm involved with the Guardians."
Gunn recently confirmed that GOTG Vol. 3 is still on track to shoot later this year.
Plot details are under wraps, but we know the main cast members are all set to return, and although Gamora was killed off in Avengers: Infinity War, the character is expected to play a major role in the plot.
This obviously suggests that the alternate timeline version of Gamora who was introduced in Endgame will end up joining the crew. We might also see the return of Sylvester Stallone's Stakar Ogord/Starhawk, Michael Rosenbaum's Martinex and the rest of the original Guardians, but that's still up in the air.