My guess (pure speculation) is that Wipr sets the fingerprint to a well-known value for privacy / anonymization reasons, and Meta is indeed using that to suggest related accounts.

Wasn't something I expected -- seems to be related to having Wipr Extra enabled. Emailed the dev about it and will share if I hear anything back. For now I have it uninstalled and have not experienced this since. Recorded a video of enabling Wipr Extra and the auth page refreshing to show three random people, might be a pain to redact it but I can try to if people really don't believe me.