Someone should probably create these (I don't believe I have the rep). Further, since it appears the iPads won't bear numbers in their trade names the way iPhones do, is it effective / worthwhile to continue making separate ipad-4, ipad-5, ipad-mini-2, etc. tags for each, or should we treat them more like Macs, which don't receive a separate tag-per-generation?
I've created an ipad-mini tag and will watch it so see things are going smoothly. If you want to make a new question (or an edit here) linking to some questions that need ipad-4 I'll gladly do the same.
As to the utility of generational tags, we have a chat room to bang out ideas and can always schedule a meeting if people wish. Anyone can also ask here to form community consensus about merging existing tags / make the case for or against having separate tags for each generation.
In general, tagging things with iPad (and only iPad) lets people find and answer questions and the iPad 4 LTE / AT&T sub model specifics almost always are discoverable and searchable via the text of the question or the presence of auxiliary tags like cellular-data or lte in conjunction with the ipad.