"A while" is an undefined period of time.
6 hours ago to now would qualify as "a while"
So would June to July/August/September/October etc.
He's really only saying it because game development is pretty volatile and can change on a whim if something goes wrong so it gives him leeway.
3 months is a while and this type of situation has happened before where he says one thing and goes completely against it
I guess everyone’s just forgotten about the time when sakurai said “I kinda hope you aren’t expecting many base roster characters as we’ve made bringing everyone back our main goal”
Same type of situation. We ended up getting 10 for base roster even though he said don’t expect many base roster characters so sakurai saying we’ll have to wait awhile doesn’t mean we’d have to wait till December
It's 11 newcomers in the base game
In the context of Smash, 11 is the lowest we've gotten for base game newcomers so I wouldn't consider it to be "many" to be honest, especially when you consider that 5 of them are echo fighters. Even considering Melee's clones, it'd still have more unique newcomers than Ultimate too.