As far as the multi-part episodes, I don't think anyone would object to them being 4 or even 6+ parts. Each map can be it's own release, which will lead to players playing that new map multiple times, instead of releasing all at once an endgame grind only working with the last map in the list. And each hero can get a dedicated release so players can get drawn back in to experiment with them and level them up.
Point being, it's more important to have something new released faster than to have a lot of new things in a bulk update that's spaced out.