To put things into perspective, here's how the series were announced:
was announced on Sept 29, 2019
That was the same date when SM 141 was airing, the episode where Ash starts his exhibit match with Professor Kukui.
Pokémon Sun & Moon Anime
was announced on Sept 15, 2016
XY 136 aired, the episode where the Team Flare arc reached the climax and finish, but with still a few things to wrap in Kalos.
was announced on June 30, 2013
Two weeks ahead of Alexa's debut, which introduced Gen VI Pokémon to the main series (as well as Ash leaving for Kalos). Also, the Decolore Islands were essentially filler.
Pokémon Best Wishes
was announced on July 1, 2010.
By that point, the Sinnoh League was starting up. And by the time Ash vs Paul battle reached its conclusion (plus Tobias), previews of the next series were up and running after the episodes aired.
What these series have in common is that they were announced near the end of each series, but early enough to get viewers ready for transition as the wrapping up begins. Typically, they get announced after some big finale has finished or still going on but reaching the end. So naturally, the new series should have been announced after Ash defeats Leon.
That would have been the perfect time to announce SV anime. And cutting close since SV was coming out next week. That was a very late yet optimal time to announce SV Anime...
But no, nothing. Not even a leak about it. SV games are already out but the anime only showcased one IX Pokémon thus far... and in a Team Rocket short that doesn't offer much hints. Plus, it's after the games are out. This is unheard of. The anime has never been late to promote any new Pokémon games. It's always been on time in Japan.
There's not even a leaked poster out. You think at least that would have made it on the Internet. At the very least, tell us what the new anime is.
This is why I suspect a hiatus for months ahead, if not outright ending the Pokémon anime series as we know it. The hypothetical SV anime is overdue, and there may not be enough time for the anime to cover the games before the next big thing for Pokémon arrives.