According to a recent foreign media report, a source close to Pokemon: Purple and Purple said that the game will release DLC after its release later this year (November 18).
The message came from Twitter user @riddler_khu, who, for whatever reason, made his account private. In the past, he has shared a lot of information about zhu/Zi's plot, although the accuracy of the information has not been verified, but insiders say that a lot of it is quite reasonable.
Pokemon Sword/Shield has two DLC titles following its release, and that tradition should continue. However, the studio will decide whether to continue to provide new content based on how enthusiastic players are about the game. We still need to wait for the official announcement.