Ever since DLC characters were announced for Super Smash Bros. Ultimate, people have been begging to get Goku from Dragon Ball to be in the game. Unfortunately, it has not happened and there's been no indication that it would. This week, game director Masahiro Sakurai has decided to dash your dreams by telling you it's definitely not happening.
The news comes from PushDustIn, an indie Smash Bros. journalist who covers pretty much everything related to the series. That includes translating small news items as they come in. Below is a video with a quote in which Sakurai basically says that the only characters that will come to Super Smash Bros. Ultimate are those from other video games and gaming franchises. Which is why you've never seen stuff like Iron Man or Batman appear in the game.
So there you have it. You have a greater chance begging Nintendo to include people like Master Chief from Halo or Crash Bandicoot than you ever will of seeing a beloved anime character or a comic book character be added to the game. Best of luck to you getting those characters in, by the way.