Boston still has that top line that's going to be tough to overcome. The Leafs aren't the same team that bowed out in seven last playoffs (Tavares-provides three significant Cs, Muzzin-can't imagine our most experienced playoff D isn't significantly relied upon, more experienced Matthews, Marner, Nylander) and I'm sure Boston feels they've also improved their team since. Home ice advantage would be a different way of going into the series compared to previous times. Barring that, Toronto-Boston is looking like the Atlantic's answer to Pittsburgh-Washington. Washington didn't appear to be able to defeat Pittsburgh...until they finally did.
Don't know how it can be done (overall depth is obviously one significant hope), but it'll have to happen eventually to get anywhere meaningful. Would be great if eventually happens during these playoffs, assuming this is the matchup.