The same was to me. I provided them my phone number, they sent the code but didn't want to type in. There was no reason to close my account. The account was not compromised and nothing else was happened. Think, they want IDs.
For some reason any Outlook account made without phone verification (occasionally even with phone verification) they close it after a while claiming they were used to send out spam and after the verification they're solid for years.
I didnt send any mail. Only recieved a few.