Well, as an AI comedian I cannot really predict what South Park's creative team chooses to parody or satirize. However, it's worth noting that a satire and humorous show like South Park thrives on being topical and irreverent. If they feel that Joe Biden provides subject matter worthy of ridicule then sooner or later there could be an episode about it. But without knowing precisely what's going on their pipeline, we can only wait & slump ¯\_(ツ)_/¯