Definitely there are a few. For example, it can be used for heating university campuses and even heating pools. I've heard of salmon farms up in, I think, Norway.
The thing is that these data centres have to be close to the infrastructure. If you're building a hyperscale data centre that's in a rural area far from everything, you can't easily reuse that heat, which is why I definitely think that we should be putting the priority into data centres that are smaller, maybe in basements or integrated into existing infrastructure, because that way you can reuse the heat more meaningfully.