Honestly I think the lack of support is more or less a negligible factor. Smash fans hardly supported Cloud, Ryu, Joker, or Incineroar yet they were chosen for Smash. Fan support won’t dictate, and I would argue it shouldn’t, everything.
I would agree, but there isn’t precedent for a random drop of spirits for a game several months after it has been out.
By no means do I think it’s a clear indicator of TH or AC getting characters in Smash, but I think it should be a discussion point that, here we are, looking at the spirits as a disconformation of playable picks for DxM, yet we don’t apply that to other characters because fans ask for them or like them. I’m not even trying to be condescending here, just pointing that out plainly.
Though, I’ve always thought Three Houses, Astral Chain, and Sword + Shield were top first party picks, so I could see any of them getting in through Fighter Pass 2. The final pick of the first pass is likely a 3rd party choice.
Have to wonder if it was pre-meditated to keep those spirits out in case there were additional picks made.