Eh whatever. Ice is such a shitty defensive typing, who cares what it's weak to, just make it offensive and fast. Weevile does fine. Hopefully the secondary typing doesn't add a 4X weakness, and they have natural bulk, then they can still be good like mamoswine.
But they could make the worst ice typing in the game (ice/rock?) and it could still be really good if they embrace it as a glass cannon.