First, remember that no piece of trivia is considered "useless"

I have never heard the IIvx classified as a Centris but then again it makes more sense for it to be lumped in with the Centris machines than the older Mac IIs since the architecture is different. The IIvx is basically an 030-powered Centris machine if you look at how the machine is built. It's got more in common with the low-end 040s than the IIci and others that it was competing against.

In late 1992 the IIci was still in production. Apple probably came up with the IIvx as one last ditch attempt to save IIci sales and to offer a new low-end for the upcoming Centris line that replaced the IIci (which was a mid-range model by this point in time). However, the IIvx never really had a chance to succeed because of the less expensive IIsi (which was about the same in terms of performance) and because of the popularity of the old IIci, the lower-end "Macs for the Masses" (at the time, the Classic II and LC II), and the higher-end models.

Apple could have easily made the IIci for another year in place of the IIvx but went with the IIvx for one reason--to save money on cases and architecture. Keep in mind that Apple was simply sticking different badges on the same cases to make many models in the mid-1990s.

Of course, we all know what happened with the IIvx...hence the term "IIvx-ed" that's still in use today...