Probably likely, unfortunately.
Apple seems to be at some sort of crossroads on their desktop offerings. iMac neglected, but Mac Pro, Mac Mini and Apple displays basically abandoned.
With the pressure from Microsoft's Surface all-in-one, I think they will need to respond with some sort of new physical design if they want to stay in the desktop business.
Given their reduced interest in displays (those large 27 inch things do create logistical problems with shipping and warehousing) It wouldn't surprise me if they come up with some sort of "super Mini" approach with all the electronics in a small box that they can market to Mini / iMac / Pro customers with the support of 3rd party displays.
Such a box could be designed with user access to RAM (and other things), but given that their last Mini design had soldered-in RAM, I'm not hopeful.