This is the slope having already slipped.
It's not a fallacy to say that this is gameplay features for pay and I am only ok with cosmetics being for pay in a game that isn't free at its base.
I don't want to let them move that goalpost.
Also, not all slippery slope arguments are fallacious. https://en.m.wikipedia.org/wiki/Slippery_slope
While it is possible that a company like Capcom, driven to increase its profit margin, and having normalized pay-to-win-through-convenience-features in this game would choose to not do more pay-to-win options with deeper gameplay impacts in a future game.
Being vocal about hating this game's micro-transactions, especially with the reviews going so negative, is one of the only ways we can communicate that we don't want either.