This episode was meant to air as the season 4 finale, but due to the Covid-19 pandemic, it was not able to be filmed in time. By the time that it was filmed, to be a part of season 5, Julia Butters had left the show. So, the character of Anna-Kat is played by a different actress, even though the graduation takes place during the timeframe of season 4.
Last episode of actress Carly Hughes (Angela).
Although Ali Wong was credited as a main character for Season 5, she only appeared in 6 episodes (Episodes 1-5: "Graduation" - "Kids These Days" and Episode 7: "Under Pressure").
Giselle Eisenberg takes over the role of Anna-Kat from Julia Butters.