It's About Getting a Gun Certified for sale in CA
To the best of my knowledge, CA law does not require a 1911 type pistol to have a FPS. That's why some of the other guns you mentioned, like the Wilson, et al, do not.
CA law does, however, require that all hand guns sold in the state be "certified" and that process is difficult and onerous for the manufacturers. Based on multiple discussions with Kimber personnel re: what it takes to get a gun certified in CA and what guns they do or don't plan to certify, they indicate that the best and perhaps only way to get a gun certified in CA today is to be able to link its heritage to another gun that is already certified and say that "x is the same as y, therefore it should be certified". In Kimber's case, since only Series II guns with the FPS are currently certified, only other FPS type guns can then be certified as well, going forward. This certification, unfortunately, extends to such minor differences as color (i.e., a black gun and a stainless steel gun have to be individually certified).
The Warrior or its colored counterpart, the Desert Warrior, are Series I guns (no FPS) in every other state but CA. In CA, only the Warrior II, with FPS, is certified and approved for sale. It's not rational but it is what it is.
See
http://certguns.doj.ca.gov/ for the list of all guns certified for sale in CA or sort the list in various ways on Kimber to see what you can and cannot get.