I'm pretty sure both x5 and x7 will share this new redesign but with different set of features. Ther emight even be room for an 'x3' that cuts out some of the features like the 'RTC' to save money.
It wouldn't make sense to make two different models with same feature set and charge more for the 'smaller one' when the parts should be about the same price for both... It's much easier to just build with one design in mind as well, rather than creating confusing two models that 'do the same thing'. Say for example following ED-GB line, X5 costing $90-100, and x7 costing $120-130.... If they do the same thing, instead of selling both he should only sell the new one to avoid confusion...
Infact, if they are the same things (except maybe a upgraded FPGA), maybe going the route of "N8 Pro" or the "SD2SNES Pro" would make for a better naming convention... Even SD2SNES Pro went through two revisions one that was full size cart (like Famicom) size, and the others that were smaller and could fit in a SNES style case.