I don't see how people are saying this makes sense for the Leafs. Leafs have exactly 1 hole on defense right now, and that is a true shut down D to play with Rielly (and Barrie playing like a top 4 D again).
Both of those guys would be brought in to upgrade the bottom pair. Holl has been outstanding and is the exact thing the team needs.. Shutdown ability, size, toughness, clearing the crease, laying hits, etc. Meanwhile Dermott is on the bottom pairing.
Only way this makes any sort of sense to me, is if Dubas wants Fleury/TVR for the bottom pairing LD spot, move Dermott from LD to RD with Rielly, and then trade Ceci for something to have some cap space to make moves.
However in that case, you would assume they would try Dermott on the top pair for a few games first to see if he is any better than Ceci (who has been pretty damn average in a good way in that spot).
I don't see it. Leafs don't have much use for bottom end roster players. They badly need a backup, they need their top 6 to start playing like they aren't terrible, and need a top 4 shut down D preferably with size.
Maybe throw in a top 6 F like a Ferland or a Wilson which is a dream list scenario as they are too rare.