I don't think they'll be doing such short-and-fat cells unless there is some specific application where they would be needed.
It looks like they are just making slightly bigger batteries that can still be used with the same cooling design and such, possibly upping the power density of car battery packs a bit.
These are not the most energy dense systems possible though. For example the ones on jet airplanes use rectangular cells and pack more per cubed metre that way, but those have been prone to serious problems in the past years.
I doubt we will see many of these cells outside automotive use though, 18650 has become the consumer standard to some degree. If they only use these 20700 or 21700 cells in car battery packs that would mean you'd have to harvest them from such car batteries, yieling a very large number of cells in each go.
18650 lithium cells were not really intended as a consumer product to begin with, but china has taken care of that putting them in replaceable sockets on all kinds of devices. I don't really blame them, the best thing before that were AA or AAA sized NiMH batteries with low cell voltages and energy density.