I don't what's really a test for what. I don't think DQXI is going to have much of a tail on any platform, its a JRPG and, bizarrely, they moved *backwards* from DQIX by removing the multiplayer component entirely. So used or not, after the first few weeks (and pre-launch weeks, ala now) most people interested are going to jump in and that's it. Used copies vs. shipped is going to potentially result in another mess like FFXV, though, so that will depend on SE's plans here vs. how much they can get retailers to buy.
From there, as per sinobi's analysis, others (probably 3DS) are just content to wait for the switch version. 3DS in general has also slowed its ability to move software in its old age.