They're not really "what ifs" with no evidence though. They're predictions of Nintendo's tendencies based on years of Nintendo's tendencies: their unwillingness to embrace competitive Melee, their unwillingness to acknowledge the existence of Project M, their hard-line stance that Smash Bros is a series of party games.

For Nintendo to appease this community, they'd need to renege on years of what is essentially their core values of Smash. They are a company that wants to make money, yes, but they want to provide a fun and engaging experience for everyone, including people who have never held a controller. I would dare venture that they are not at all interested in putting in the time, effort, and money that it would take to release something that actually satisfies the community's high expectations -- especially when it's a community they hesitate to even recognize.

Think of other HD remakes they've made, and ask yourself, would they make Melee HD the way the community wants it? Would everything tech-wise be the same? Would things like shield dropping or directional air-dodging still exist? Would they remove port priority's influence on chain grabbing, or the clipping issues with Pokemon Stadium? It's not simply what-ifs if the "fears" are predicated on highly realistic assumptions of this company.