I'd like to address something:
While I was originally the one who said that DLC was planned when the original roster was decided in December 2015, I've since come to doubt that statement a little more.
The DanMan051
's argument about context got me thinking that we (read: I) might've taken the statement too far in applying it, and I'd like this to be known before others go spreading it around the internet (I'm sure it already is, Sakurai help us all).
Obviously, DLC has been in planning stages for a while, seeing as both Minecraft and Square Enix content have been known about for months but have yet to appear in the game, which signifies that they'll likely be DLC. However, Senrou_Hitagi's comments about recent talks between Nintendo and Cygames (occurring about 1-2 months ago) make me think that
DLC could've been planned much later than December 2015, or at the very least plans for DLC were flexible up until negotiations began.
Ultimately I believe that DLC wasn't planned out as a whole, but characters were planned individually as negotiations occurred. This would explain why information about certain DLC elements (Minecraft, Square Enix, Cygames) came out at different points, because nothing was known until negotiations either ended (in the case of Minecraft, Pre-E3, and Square Enix around September) or began (in the case of Cygames, around October, which makes it absolutely last second in terms of negotiation and planning if Senrou is to be believed and Katalina is going to happen).
What I'm saying is that negotiations, and therefore planning, for DLC could've occurred anywhere from December 2015 to October 2018, with different characters being planned at different times. I wouldn't necessarily give up hope for more recent characters (i.e. Rex and Pyra, Bethesda Rep, Crash Bandicoot, etc.), but I also wouldn't get them up either.
Nintendo characters in particular seem to be facing an uphill battle as well, given Verge's other statement that Sakurai prioritizes third party characters for DLC over first party characters.
I'll make sure to pour one out to the fans of whoever got cucked out of Smash by Katalina.