Please! I was just thinking about this and specifically visited forums just to show my support for such an item! I have this lad that I'd absolutely love to apply the alternate pose for, but I really want the wolf itself to remain as a male.
I'm drawn to more poses than others for a breed (stares at M. Lupin) and so it would be great to be able to have a wolf breed change pose wise without just switching the sex.
"I laughed with you. I believed in you. I followed you. I cried for you. I fought with you. I grew up with you. And all along. You were never really there."
As long as there's a little icon to denote they've been swapped around I don't see any problems with the idea, you could potentially make it a semi-hefty pebble sink since it doesn't come with the "advantages" that sex-swapping does for breeding goals. It can add some more variety to a cave, let people get more out of their apparel, sometimes different poses just vibe better either for aesthetics or for character personalities, whatever.
The desire for them to be marked is purely just to dodge unexpected landmines on the flea market while looking for breeding stock. While it's not the end of the world to filter the this-sex-only toggle to make sure you're buying the dog you think you are... It would be worthwhile to just mark them out of the gate and avoid confusion and problems for new folks or people in a rush. There tend to be so few dogs available for the obscure color combos I'm always looking for, it's just not worthwhile to get into the habit of filtering more than I absolutely have to. :P