As a biologist myself, I am unsure how I feel towards "de-extinction" in general. It's a really complicated and unknown area. I'm not sure how feasible it is. There's a lot of factors there to consider, such as how that would effect the environment, the possible shift of food webs if the animals were reintroduced. Not to mention the cost.
I think it would be *neat* if the Auroch were brought back, but I'm not sure outside of that what kind of value they would have. If Heathens were to interact with them it would likely be several, several years down the line. I do think it could hold some signifigance with it's connection to Uruz. But it's all iffy to me.