Min Min was a pretty solid choice in the grand scheme.
I wasn't really an ARMS fan but the guessing game for the fighter did an effective job of keeping the fandom somewhat occupied during the early days of the pandemic and absorbed a lot of the potential blowback that including such a character might have gotten if they'd just shown her off then. She made a pretty decent rep for her home series overall, and while I would have preferred one of the wackier selections just for the sheer visual novelty, she's still distinct enough that she doesn't feel generic. Having one of the better trailers, complete with a stunning animation style, certainly helped.
As far as her as a fighter? I tempted to laugh a bit because as someone who doesn't play online and has only faced off against her a number fo times, I suspect my play style is probably the ones that fans find most annoying. At the very least, though, having a stretchy arms fighter like her felt overdue, and she's an effective compliment to the Belmonts in some respects, whom I also enjoy playing as. She's probably the most middle of the road DLC character for me, not quite as satisfying as Banjo or Byleth, but more frequently selected than the likes of Joker or Hero.