When do you share tenant personal information on sale?

[Jacob Marble]

We're going to close a sale on a 10 unit building in Missouri in about two weeks. The buyer is asking for our tenants' SSNs, phone numbers, etc. My property manager says it's illegal to share, and refuses to comply. I feel stuck in the middle, just want the buyer to get what he's paying for.

What's the right answer? I don't think I've ever been offered tenant personal information when I bought. New management needs to write new leases anyway, right?