Plenty of guys are high AHL scorers and never earn their place at the NHL level.
Gushchin is a good prospect and at his age you’d expect him to get several good opportunities to stick still but rightly or wrongly, you have to consider system fit (does he play the “Mike Grier way” is kind of a derogatory meme at this point) and also overall depth.
People clown on clubs like San Jose and Columbus for being bad but that doesn’t mean they lack depth. On the contrary, their years of stacking prospects and selling veteran stars into multiple pieces leaves them somewhat bloated with pro options for depth roles and then those guys start to run out of waiver options so it suddenly isn’t purely about picking the 20 most talented players.
Now, we can certainly argue if adding the likes of Goodrow and Dellandrea before the summer even begins at the expense of giving internal options a better shot is a good idea - but October is a long ways away so I don’t think I’d write Gushchin’s obit with SJ quite yet.