I wouldn't think so myself. The official media for the resin (and better looking, IMHO) XV8-05 always described it as a generic commander model, with no mention whatsoever to any named character. It's also telling that as far as I can tell the only official studio photos for the model were taken in the 6th edition T'au desert camouflage scheme, while a Farsight Enclaves colour scheme would be more fitting if it was indeed meant to be an Enclave character. The reason for those weapons in the resin kit was to provide sculpts for special issue weapons that would otherwise be unavailable, with the special plasma rifle as a little extra bonus.
Indeed, my guess would be the opposite - after the resin XV8-05 model was made, one of the studio writers decided to incorporate it into the background around Farsight's entourage, and created the character to fit the model rather than the other way around.