It all comes down to greed & profits im afraid, my take on it is this....
Sideshow originally commissioned the sculptor to make 3 heads with the intention of offering at least one of them as a switch out extra, they planned on selling these LSF Wolverines at $2000 with an extra head included, but then someone at SS realized that they could charge the same price but only offer one masked head and people would still buy it, saving SS a great deal in production costs and making them a tidy profit in the process.
I can fully understand Martin Canale showing off those incredible extra heads and his apparent disappointment and dismay at them not being used, if i spent as much time an effort in sculpting such wonderful head sculpts only for them to never see the light of day then i would want to know why as well.
The only thing to do would be for everyone who has already ordered this piece to cancel their order and basically demand that they include at least one of those extra heads, but i know such a boycott will never happen.
Protest with your wallet people, if enough people cancel and state the reason why they have cancelled then we could twist Sideshows arm to get these included.