I think it’s pretty reasonable to expect a Direct simply based on the fact that Best Buy has the Joker render, and I would assume the information about the other leaked games.
Would it be as robust as the previous Direct? That I can’t say. I could see some more information on already announced games, like the 3.0 update for Smash as well as Mario Maker 2. Then announce stuff like the Metroid Prime trilogy for Switch, ALttP, etc...
However, the longer we get through April, the closer we get to E3, which means less reason to have an “all out” Direct. Unless, of course, they’re focusing on a select few titles at E3. I think it’s obvious we’re getting at least 1 DLC character at E3, but I almost have to wonder if Joker is all we’ll know about going into E3.
Who knows? The Mewtwo gameplay reveal also showed off Lucas afterward, so who says the same can’t happen for Joker and Erdrick?