> the datacenter doesn't have a few million dollars to spare.

What makes you think so? Datacentres are already very expensive, and getting permissions quicker (or at all) might be worth a couple million dollars.

> The heat is waste heat. If it cannot be recovered as a profitable source of energy, [...]

Yes, they should make all deals that make sense for both parties, definitely. But it's only viable in some places some of the time.

Recovery isn't the issue, the issue is that district heating systems are pretty much a rarity across the world for a number of reasons. Recovering waste heat - no matter if from datacenters, industrial processes or eve wastewater/sewage - is trivial, but getting the heat to somewhere it still can have a productive "secondary usage" is a massive and expensive problem.