With the number of 3* and 5* characters increasing lately, this will likely drive away newer players. For new players and those of us who regularly keep characters who are frankly pointless (but we still like them), how about thinking on how missions are set up?
It would make sense to have missions that are star or level capped to make use of these characters? (Let's face it, how many of us use 1* or 2* covers outside of Deadpool's Daily?) Maybe a 4th required character (but required star instead) mission per event?
This could give newer players an easy way to shine and allow us veteran players a way to use those extra characters.
With players starting to use champions 2.0 (for some reason), this would give them a chance to build those characters and play them.