As most animated programs require a year of lead time from initial voiceover work to finished, fully-animated product, it's likely that the majority of the 20th season of "Family Guy" already exists in some pre-production format. Since animation doesn't tend to suffer from the same scheduling issues related to the COVID-19 pandemic and other attendant production delays, it's likely that the upcoming season will debut on schedule with its previous season premieres, likely first airing in late September or early October before taking a brief break due to the World Series.
The latest that "Family Guy" has ever debuted in the year was in Season 16, which arrived on October 1, 2017, per IMDb. Meanwhile, the earliest was in Season 3, which premiered on July 11, 2001. The latter's debut schedule was likely related to how Fox had burned the show's third season off over the summer months after canceling it. Adult Swim and DVD sales ultimately rescued "Family Guy" from the dustbin, and that resulted in a new season four years later.
