When are we going to acknowledge that distinctions like "tablet" are anachronistic in the first place?

It's all about the software platform. I'm sure the folks at Google make little philosophical distinction between the Android "tablet" software and the Android "mobile" software, for instance. Nor does Apple call its iPad OS a totally different name than it calls its iPhone OS. Other than some minor cosmetic differences, the code is 99.9% the same.

Tracking share in the "tablet" market is going to seem very silly in a few years.