Theres no "trial", its a contract. You don't play without a contract. They're asking him (allegedly) to play in a deep playoff run with the crunch and come to camp next season to take the next step. AHL salary is what it is, you can still negotiate signing bonuses. If you're going to boohoo the money thats fine and I get it, but he'll still be capped in what he can earn on his ELC wherever he goes, so i'd presume its more about the minutes than the money.
Ultimately if he thinks he has no chance on this roster, hes probably right and they should trade his rights. I would personally prefer to try to work my way into a more successful team, learn from people, but i'm also not 21 with people throwing six and seven figure numbers at me. I think he is incredibly talented and it'll suck to have to lose him, but I do still have questions with how long it will take him to adjust to the physical game due to his size.