The Ultimate editions were probably released because it wasn't possible (or was highly difficult) to release expansions for games on the PS2 and 3DS. Now that it's doable, it'll be the model going forwards. Each time Capcom have added new content to the series, you've needed to pay the price of a full game - the content in the complete edition you've suggested is an expansion by another name, with a lesser story. Which is a downgrade.
Then, if the switch 2 hypothetically gets this Ultimate edition of the game while everyone else who got the game first has to pay for an upgrade, those 8 million players would be rightfully outraged.
So, no, Wilds should not get the Ultimate edition treatment, and no, I would not pay for the upgrade if the Switch 2 got it for free.
