Niantic has announced that the Pokémon GO Battle League Season 10 will be extended until March 1st, 2022, at 1:00pm PST.

GO Battle League: Regarding the next Season

Trainers,
As we head into the final week of GO Battle League Season 10, we wanted to let you know that the next Season of the GO Battle League will be a change of pace from our usual Seasons. We’ll be pausing ratings during this new Season to allow our development team to focus on GO Battle League adjustments without disrupting competitive play.

What this means

• GO Battle League Season 10 will be extended until March 1, 2022, at 1:00 p.m. PST (GMT –8) rather than the previously announced end date of February 28, 2022.
• The next Season will begin immediately on March 1, 2022, at 1:00 p.m. PST (GMT –8) and run concurrently with the next in-game Season until June 1, 2022. at 1:00 p.m. PDT (GMT –8). GO Battle League seasons will run concurrently with in-game Seasons moving forward.

For the next Season

• Rankings will cap at Rank 20, and there will be no visible ratings.
• Cups will rotate weekly and will feature re-runs of former special cups.
• The Season will be used as an opportunity to test some possible new formats for GO Battle Days and their reward structures.
• Attack changes or attack availability updates—as typically seen at the beginning of most GO Battle League seasons— will not be made in order to maintain stability for Pokémon Battles as the World Championship Series circuit begins.
• Rankings for Season 10 will be used to determine early registration eligibility for the Pokémon GO World Championship Series.

Please stay tuned for additional details on the upcoming Season. We appreciate your understanding as we continue to work on creating a better GO Battle League experience for everyone. Stay tuned!

Please be aware of your surroundings and follow guidelines from local health authorities when playing Pokémon GO. Upcoming events are subject to change.

Source: https://pokemongolive.com/en/post/go-battle-league-next-season-update/