That's the situation now; how predictive it is different question, one that can't be definitively answered right now. Fwiw, the characterization you bolded also applies to Jordan Poole's second healthy season, at the same age (and probably to a bunch of other guys; JP is just fresh in my mind, for obvious reasons). Fultz seems like a particularly poor comp, given Wiseman is not a 6'-3" PG who cannot shoot, nor (AFAIK) has he had any Sax/Sasser-ian issues with performance anxiety. He's just a huge, raw, athletic dude who needs to get used to the speed and patterns of the game, and has nowhere near the needed reps in which to do so. I'd be shocked if he ends up a superstar, but given his size, athleticism, and (reportedly) high character and work ethic, I don't think a career somewhere in the Myles Turner / Ayton / JaVale range is that unreasonable to ponder.
His career isn't over (Darko played for 10 years), but I don't see the Poole comp, beyond that they are both Warrior 1st round picks who played in the G league. Injury or no, there's a big difference between year 2 and year 3. Additionally the Warriors didn't have a pressing need for Poole at that time - Curry was back and playing at an MVP level, but the team didn't look like a title contender. They absolutely need young size right now (and hope to compete for a title), and Wiseman is falling flat on his face. Fultz isn't a comp, other than both guys looking like massive draft busts. Comparing Wiseman to Poole (or Looney) kind of misses the point - if Wiseman had been drafted with the 29th overall pick instead of the 2nd, nobody would bat an eye on this, because we'd know his odds of being in the NBA in 5 years are 50-50 at best. Those guys beat the odds, guys sent down to the G league in year 3 don't have a great track record.
Turner and Ayton were productive from day 1 (Turner started 30 games his rookie year for a playoff team while Ayton averaged 16 and 10 shooting .585 from the floor), and just as importantly, they were actually on the court for most of their first few seasons. Maybe those guys are the upside possibility for Wiseman in a few years, but the Warriors need the help NOW while Curry is still MVP caliber. That upside looks incredibly far away at this point.
Javale is a different kind of story - Javale at his best would be nice, but it's with good reason that he's changed teams 9 times in his career. If he hadn't lucked his way into two titles with the Durant/Steph Warrios, his career highlights would literally just be a blooper reel.
*edit - Who is the best player to play in the G league in year 3 or later? Here's a list from 2021 with the most successful NBA players to ever play in the G league:
Poole would undoubtedly be on an updated version of that list. Of that group, Danny Green is the only one to even play on the G league in year 2. Everyone else spent time there as a rookie, and that was it.