The requirement to list social accounts has been present since 2018, and the FAQ [1] says: Visa applicants who have never used social media will not be refused on the basis of failing to provide a social media identifier, and the form does allow the applicant to respond with "None."

https://ie.usembassy.gov gives 504 so I can't check the primary source, but it seems like the new part is a requirement to make accounts public and applies only to F, M, and J student and exchange visas.

[1] https://travel.state.gov/content/dam/visas/Enhanced%20Vettin...