Dave has said he has done it. ‘nough said. I see a lot of glass half full guys here. It can’t do this, it can’t do that. Why not just wait until its released?
I didn't say it wasn't possible but go find the needed adaptor for the same price as a usb-a version... I have a dozen or so of those just laying around.
Plus, who is still using micro-b? It's a dying connector. A usb-c connection would have made much more sense.
I never doubted the ser2 being able to acomplish this and by the time you even find the correct micro-b to serial cable, the ser2 is probably the cheaper route.