Eventually, writer Aaron Allen presented a script that Aguirre-Sacasa saw had a very Leave It To Beaver type dream sequence, and the pieces fell into place.
The team got to work transforming the scene to fit their vision of classic Archie, and the sequence of what was shown on tv was officially created.
As far as other reasons why Riverdale showed the sequence, Roberto Aguirre-Sacasa said it had always been a goal of the series to somehow work in the classic outfits of the characters.
Aguirre-Sacasa tells EW several options were considered to work in the costumes, including flashbacks of the show’s parents wearing the clothes in high school.