Official? Official by what standards?
For each Smash game, there are community tier lists created by the overall Smash community figureheads.
They are typically done by the Smash Back Room, but that currently does not exist anymore.
Between that, the larger roster of Ultimate, and the stagnate metas of Smash games that isn't Melee or Ultimate, all means that they are no where near as frequent as they were in the 2000s/early 2010s.
The current one for Smash 64 was made at May 15th, 2015 by the Smash 64 Community, fairly outdated but the 64 meta is fairly stagnate right now.
The current one for Brawl was made at April 25th, 2013 by the Smash Back Room.
The current one for SSB4 was made at December 11th, 2017 by the Smash Back Room, also outdated imo since it excludes 2018 meta developments.
As such, modern Smash tier lists are now being done via aggregate complied from most of the top players of the world. Melee did this with their current tier list on March 29th, 2021, made by PG Stats. Perhaps someone in the thread can explain this a bit better, but that is the gist of it.
However, no top-level community made tier lists have been made for Ultimate. Now, after over 4 years after the game's release (which the longest it has ever taken for an official tier list to be made for a Smash game between its release and the tier list's creation) we are finally getting one.