I can only assume this will act like a soft-reboot, which may also be the end of the series.
I’m a huge fan of Euphoria, both seasons and the specials, but I just have a hard time seeing this show continuing. So much of what made this show work comes from them being young and irrational. The older they get the more the show would just become one about drug addicts (which to be honest is already a big part.) That’s a story you can tell, it’s just going to be a different show and I’m not sure you can go far with it.
BUT, if this is a final third season, give it a shot.
And there’s only so long you can play high-school kids for, of course - Alexa Demie is 33! (though her birthyear doesn’t feature on her IMDB profile, interestingly enough)