The dlc characters were decided in November, 2018.I guess my mindset at the moment, is that post fighter pass is the first opportunity Sakurai really has to address the demand for characters like Waluigi, Geno, Isaac, Dixie etc. So if he doesn't start with one of those characters right out of the gate then it starts looking less likely that that's even his intention to begin with.
This is assuming Sakurai didn't have full control over the fighter pass since Nintendo presumably provided him with a list of possibilities. (also assuming that characters on the fighter pass were decided on before the release of Smash Bros Ultimate)