Meta recruiter asking if my referral would give feedback post interview

It's a positive sign meaning that they care enough about you to follow up and do some sort of reference check.

In terms of expectations: [Meta Hiring Process] Meta recruiters request references before submitting feedback file to review committee

Meta has always done this, but I think them asking for it is more pronounced now. I don't know if they're only doing it for candidates that have done well or all of them, but I agree with Rahul in that it probably means that you did solid (at least "Weak Yes").

In short, the references help but aren't required. Check out this thread: "Can you please suggest me any names from Meta to put as references?"