I'm not sure what you mean by positive value, but if Barron doesn't offer positive value, I'd also argue that Xhekaj, Newhook and Dach don't either (due to injury, usage or impact). Slafkovsky also didn't offer any positive value in 2022, but definitely did last season. Montreal's rebuilding, the hope is that he can in the future.
As for Laine, it depends on how realistic we are, but Montreal absolutely has pieces Columbus would want. They clearly want a more two-way LD with some size who can play higher in the lineup. Montreal has Guhle (who definitely is not available in any trade centered around Laine). They'd also be interested in Xhekaj (who Montreal probably doesn't want to move). They'd probably be intrigued by Struble, but not nearly enough to have the trade center around him.
But the real question in the event that Montreal is interested in Laine (beyond if Laine is ok with a Montreal), is how much of a market is there for him and what will Columbus be willing to do to make a trade?
Because from Waddell's comments, it doesn't sound like Columbus wants to retain a ton and it doesn't sound like there's significant interest in him from other teams. Montreal's interest should be based on being able leverage their ability to absorb the cap hit (8.7 mil for 2 seasons) and real salary (2 mil in bonuses which may have been paid and 7.1 mil in salary this season, 2 mil in bonuses and 7.1 mil in salary next). We've seen Montreal leverage their cap space AND ability to spend in each of the last two offseasons even when other teams have theoritcally been able to make the same kind of moves (without going into LTIR). Its not the flat cap era anymore, but that doesn't mean every team with cap space wants to spend real money to the degree Montreal has been willing to.