I like to think that DriDim doesn't have standard character interactions in the sense of "personalized dialogue" but does have loading screens depicting characters meeting off the track in both combat and slice-of-life scenarios. (as well as some vehicle training and car engineering stuff)
And I'd personally like to keep Jigglypuff because I like keeping the Original 12 intact.
But I'd be happy to swap out all the other Pokemon and not have any of them be starters.