That's the five-dollar question, I guess. WillMyPhoneWork lists two sub-versions of the Pro 5, the M576 (Global) and the M576U (China). Whether the Ubuntu version is one of these or a third version isn't obvious to me from what I've read. The jd.com web page doesn't mention anything about model number. But it does call it dual-SIM.

Me, I'm excited to try the improved "daily plugging-in experience".