mind detailing some of those reasons? certain areas of his game, or physical development?
Honestly ... I think it probably has less to do with him in many ways and has way more to do with Jim Nill. I get that he may not be the GM (just like Bowness technically may actually still be the coach next season despite what I alluded to in one of the posts), but he's the GM right now and under contract season. That's not an endorsement for him being fired or remaining in his current position, it's just a fact.
So basically I'm looking at this question through that lens. Right now, Jim Nill is the GM of the 2022-23 Dallas Stars.
1) Nill is notoriously slow to promote young players. He believes in them being overripe and spending time in the AHL. Outside of Val Nichushkin (and please correct me if I'm wrong), I can't even think of a 20-year-old forward to make the Dallas Stars with Nill as GM. Even Robertson spent his first-year pro in the AHL. The fact that Dallas also has a top prospect like Mavrik Bourque whose contract starts officially next season might give him an edge over a junior-aged player like Stankoven. I find it easier to see Nill keeping a 20-year-old in the NHL over a 19-year-old if all things are equal ... and it's definitely not impossible to think that once Bourque, Johnston, and Stankoven are on the ice together in August for the WJC, September for Traverse and camp ... that none of the three can really separate from one another because they all seem poised to have a chance to make significant impacts in those showings.
2) Wyatt Johnston. It's hard for me to wrap my mind around Jim Nill playing one junior-aged player in the NHL let alone 2. Both Johnston and Stankoven are poised it seems to be significant contributors in Dallas eventually ... probably very soon. I know people really want to rank players ... it's natural, but I'm not even simply stating Johnston is better than Stankoven. That said, as a two-way center that has a much better chance at sticking in the middle for his NHL career than Stankoven, Johnston probably has a leg up. I just don't imagine Stankoven is a guy that will start playing in all situations immediately at the NHL level, but I can see that as something Johnston would be more relied on right away ... thus giving him an edge in sticking at the NHL first over Stankoven.
Stankoven (and Johnston for that matter) are not going to have the luxury of coming along like Jacob Peterson this year in a limited role. If they don't immediately hit the ground running, capture significant roles, and produce ... they're going down ... and they only have 9 games to convince Dallas they're capable of it over an 82-game season at just 19 years old. That's why I think physical development and his current game might have less of an impact on the decision. It often does in Dallas. Jim Nill isn't going to let either guy play a limited NHL role at 19.