This revelation seems important because it appears to answer the question of how Michael Rooker is currently listed as “rumored” on the Infinity War cast list on IMDb.
The character may return in a flashback sequence (or even someday receive a movie of his own), but his cremation at the end of Guardians of the Galaxy Vol. 2 is the chronological end for the character.
It’s pretty much impossible to misread the guy’s intentions with that character; as long as Gunn remains involved in the Marvel Cinematic Universe, he will not resurrect Yondu for any reason.
James Gunn recently took to Facebook to answer fan questions about the future of the Guardians of the Galaxy franchise, and he made sure to keep his opinion on Yondu’s death as clear as possible: it needs to stay permanent.