Breh there will never be a series of Batman movies without The Joker. It'll never happen. People were looking for Joker clues in the new "Batman V Superman" trailer.
Can you do other shyt, add other characters? Of course. Will people like it? Possibly. But people will always want The Joker. It doesn't matter if it's movies, or comics, or even video games.
If you disagree
but it's a bit early in the MCU to complain about Hydra, any way. They've only been in two Captain America movies, three counting "Civil War". Aside from an off hand reference or a couple side characters they haven't been in most of the MCU.
Fred.