Where does it say that? Your source only says profiles need to be public
Moreover your description is slightly misleading because it only applies to "all applicants for F, M, and J nonimmigrant visas", which notably excludes tourism visas (B-2). The visas listed all seem to be academic related, presumably because the administration wants to crack down on woke ivy league students or whatever.
> "THE US EMBASSY in Dublin is tightening its visa requirements, saying that future applicants looking to visit the country will be required to divulge “all social media usernames or handles of every platform they have used from the last five years” on their visa application form."
https://www.state.gov/releases/office-of-the-spokesperson/20...