Meta has 100% already made shadow accounts for you across their ecosystem.
They’ve been doing that for just Facebook for at least a decade at this point, with the primary intent of tracking online activity of literally as many people as they can. Much of it is done in an “anonymous” fashion - tied to device MACs, IMEIs, source IP, etc, along with cookies that they’ve persuaded most SaaS companies to integrate on their sites (and often apps), instead of tying it directly to your PII.