Indeed, in an ideal world, Kent Hughes would trade Justin Barron and Jordan Harris, but it doesn't work that way.
To receive, you have to give, and the two aforementioned defensemen don't have much value on the trade market.
Struble has shown everyone his athletic qualities. He's an excellent skater, strong as an ox, solid defensively, and can support the attack, plus he's willing to drop the gloves when necessary.
He has essentially forced the Canadiens' hand to keep him in the NHL. With 10 points in 57 games as a rookie, that's more than respectable, especially since his role isn't to score.