Having depth at any position is a good thing, but only up to a certain point. The Leafs currently have 22 forwards who should (not including Frederik Gauthier and Brendan Leipsic) play at least some time in the NHL next season, and only have room to play 12 or 13 of them. Meanwhile, on defence, the team has eight defenders who are likely to play in the bigs, and so carrying an extra forward may not be an option - they currently need the space to keep their defencemen. It sure looks like a trade is coming.
The following table represents the Leafs' forward depth in what should be approximately the order the team sees the players.