The Pokémon Company International Press Release said:The forthcoming special episodes not only celebrate Ash’s monumental achievement, but they also act as an expression of gratitude from Pokémon to all the fans who have joined him and his partner Pokémon Pikachu along the way. Fans can also look forward to what’s to come in the new animated series, which will represent everything they love about Pokémon animation, including action, adventure, friendship and Pokémon.
This won't be the end of Pokémon as a weekly anime series however, with a new Pokémon anime series to start in 2023. The series will star two new characters, Liko and Roy, as they begin their own Pokémon journey accompanied by the Paldea starters Sprigatito, Fuecoco, and Quaxly. Shiny Rayquaza also makes an appearance in the trailer for this new series, though what part it will play in the story is not clear at this stage.