I don’t think Barron is an untouchable but he would certainly be hard to part with since Montreal doesn’t have anything on the right side except for Barron right now with Mailloux coming up at some point.
Mailloux and Beck are definitely on the table. Tons of Habs fans have made offer including Beck not because he’s not a good prospect but because we wouldn’t have any room for him with Suzuki, Dach and PLD at center. I think Hughes would be more willing to do Mailloux instead of Barron - Not because of what happened in his draft year but because Barron is already contributing and I bet they think they can at least compete for a playoff spot next year (kinda like where Ottawa was in 2022-2023).
As I said, Barron would be hard pill to swallow and would force Hughes to draft Reinbacher at 5. Not an impossible trade but would rather give another asset instead.