There are valid reasons to use FB pages as URL (for many businesses this is their only “webpage” and for broadest compatibility it’s OK to just use it as website=*).
If anything, there was no discussion here. (For Poland as well - which I reverted).
Sorry no.
Facebook is not an Webpage of the foreign institution. Facebook is a website of the Facebook Inc.
If an institution have only a Facebook-site - than this object have no website.
I agree it is pointless, because if there is no other website, a facebook url is just as good in “website” as it is in “contact:facebook” (as long as you can see from the URL that it is on a facebook domain, there is nothing gained).
This change includes just too much edits at once by an JOSM user.
So it would follow SafetyIng. Just ask the user first and let him improve his errors.