It still makes more sense to directly regulate the thing that actually matters. People don't really care about the presence of a DC in their state. They care about the effect it might have on energy prices and potentially the effect it might have on public land use. You can always regulate the electricity market and public land use directly, instead of regulating the construction of data centers which is more of a second-order effect.

These approaches might very well result in the same outcome: fewer DCs, but it leaves the details up to dynamic market forces.