M365 tenant blocked from purchasing any licenses, MS demanding all sorts of personal info.

I have a client who discovered they could not purchase any new licenses in their existing tenant - not business basic, standard, not even trial. They verified payment information, and even tried a different credit card. No dice. So I had them open a ticket with Microsoft. Imagine my surprise when they get the below email from Microsoft - asking them for all manner of personal information, including Facebook/LinkedIn info, Voter ID, billing info, etc. I want to stress this is legit, not a scam. Microsoft is refusing to unlock the tenant until all this info is provided. They will not say what exact behavior triggered the lockdown - the client has about 20 users and really only uses it for Teams more than anything else.

The client is deeply upset and uncomfortable with what looks like a weird form of doxxing or identity theft. Anyone else seen anything like this? It seems extremely brutal and unnecessary, and demanding such information seems deeply inappropriate. Picture of the email in comments.

EDIT: Just an update for everyone - after some back and forth with Microsoft (and an escalation after the original person who sent the email from MS insisted they needed EVERY piece of info requested, which the client refused to provide), the client reported that they have unblocked the tenant and the client can once again purchase new licenses. Still no word on what exactly caused the block to be applied, but I didn't expect MS to actually provide much insight into their procedures.