Nothing about Waluigi's outcry has been exaggerated. He's been a character that has been almost entirely ignored and has gained a following over time, getting a rather big boost in the last five or so years, much of it due to meme culture and many people sticking with their love with the character past the memes.
Also, your claim to moving the goalposts isn't even accurate, as anyone who says 'X still deconfirms' after ever fan rule that breaks are the goalpost movers, not me. Don't make me fetch that giant PNG of all the fan rules that have been systematically broken since Ultimate began, cuz I will if I have to.
No, YOU are the one moving the goalpost. The ones saying too big, too irrelevant, rival company, spirits deconfirm, yada yada. Returning costumes deconfirm is just the latest push in a lazy, weak-minded struggle to solidify speculation to try and have something to grab onto. I'm merely out here saying 'Hey, there really aren't any deconfirmations until DLC is done, so you REALLY can't count anyone out with any grouping fan rule like spirits or costumes and should look at characters and the facts around them individually' and your response is 'Give up on the characters and accept the fan rule that is fundamentally flawed just like the rest' and I just can't do that.
For example, instead of saying 'Any character with a returning Mii Costume is deconfirmed' as a broad sweeping fan rule, instead it should be a case-by-case basis, such as 'Well another Megaman character isn't likely due to all of them featuring in Megaman's FS, the fact that the added Protoman and Bass to the FS, and Zero being an AT.'
Do you see how much more informed that is? This is something I've noticed with the Smash community since the beginning: broad sweeping statements that can never hold up. No 3rd Party, no MORE 3rd party, no rival companies, no irrelevant characters, no spirits and now it's no costumes despite that not making sense for each individual character.
The fact that you can't wrap your head around active DLC and development meaning that anything can still be on the table so long as it is negotiated for, be it a character who got a costumes already or a franchise that got it's own spirit event, is absurd. 'This thing happened, and because this thing happened, the future is completely set to be a certain way.' Fun fact: you don't know what the future holds, and you are going about trying to speculate it in way that keeps getting dismembered with each character release.