^^Warner Bros operates a Manufacture on Demand service through it's online store, where classics and other films they deem not quite popular enough of supporting wide release are offered, but I haven't heard of any other studio/distributor trying it out. I don't understand how if they're releasing s2 normally, why they'd authorize Amazon to fill their orders thru a M-O-D basis.
Edit-Ok, I've done some quick reading across a few Google searches, and it is MGM handling the process in totality, not some anonymous fly by night company, so I don't think there's any reason for alarm. Not a separate M-O-D for amazon orders, and regular pressed dvds for stores as I assumed upon first reading.