Oh, definitely not, I'm just thinking about it from a game creation point of view. There are probably other options than what I listed, but if you spend over a year creating content and you've already went through the proper channels to get licensing sorted out and the like, you're probably going to do everything you can to retain that content.
I don't think we're looking at a Metaknight-in-Brawl or Bayonetta-in-4 type thing where those characters were almost clearly top tiers of their own. Joker being referenced in that article I believe was merely used as an example, I don't think they were actually implying they thought any of Smash DLC in Ultimate were a pay to win scenario.
Another thing that's a little weird to me is how exactly you determine a pay to win situation with DLC characters. Just because you have access to a character that other people don't (and in a true tournament setting, everyone would have access to all of the characters anyway, so does this even matter?), doesn't mean that they're good. I think unless there is a clear gap it'd be pretty hard to determine an overpowered or pay to win character, amongst a roster of reasonably balanced 80 characters. And like I mentioned, if that were the case and it was deemed unjust or whatever, it seems well within Nintendo's ability to just nerf that character until they no longer fall in that category.
I really don't know much about the actual law (though I do tech support in a lawfirm, hah), but it looks like various predictions put this as having a very small chance of actually passing.
https://www.govtrack.us/congress/bills/116/s1629 lists 5%, haha. Not sure how accurate that is, but I don't think this is something we have to worry about, even if it is passed.