“Your Page was flagged because your post(s) linked to domain_placeholder.com.”
Um…yeah. Sure. That’s not a valid domain name.
The message showed up less than an hour after I logged into FB for the first time in weeks, and it does appear to actually be from FB & not a phish…though I don’t see any indication in FB’s website that the page has been flagged for *anything*, much less “sharing, distributing or promoting content inauthentically.”
I’m thinking this was sent out accidentally.
Also, searching for domain_placeholder.com on FB & birdsite turned up other people saying WTF about similar messages they got in the last hour or two (and nothing older), which lends more weight to the suspicion that it’s a bogus message that got sent out to a bunch of people at once.