Apparently several gens are getting some ranking updates right now. Gen 7 just got the first update since gen 8 came out.
https://www.smogon.com/forums/threads/usum-ou-viability-rankings.3667522/The most notable change is that the rankings are actually ordered now within the tiers instead of listed alphabetically. Toxapex is now the #1 Pokemon since it's at the top of S rank ahead of Magearna and Landorus-T.
