Since Plant is a hot topic of debate, I feel like I should give my 2 cents.
Every Smash game, there's a joke character. One who, even with other reasons for being added, is there to make people confused. Jigglypuff, Pichu, R.O.B., Wii Fit Trainer, and now Plant. Plant, IMO was a great joke character. Not even people who would try to speculate the oddball pick would call a Piranha Plant getting in. But the good form of the joke is where the positives end, because with all things considered, it's not a good time to have a slot go to a joke character. As you already know, Nintendo newcomers, especially unique ones, are scarce for Ultimate. The reality for many of us is that our most wanted got deconfirmed by an Assist Trophy, or worse, Mii Outfit, or even worse, a png file spirit. It would have been far more permissible if it wasn't that the spotlight for DLC was going to 3rd parties again and that the ones who aren't explicitly deconfirmed (but I think they are implicitly) were more than Euden, Akira/Howard Twins and Byleth. But since we're most likely getting nothing but 3rd parties and aren't going to get another Nintendo character for another 10 years, it's not.
TL;DR Good joke character, but not a good time for a joke character because for the next 10 years, EVERYONE IS DECONFIRMED