If there's one large orbital datacenter, then sure, ASAT is a threat to it. But if it's a dispersed swarm like the Starlink system?
Good luck making a dent in that. You'd run out of ASAT long before Musk runs out of Starlink.
It would take zero anti-satellite weapons to take down Starlink. Just point a good old fashioned gun at the SpaceX engineer who can issue maneuvering commands to the satellites.
Starlink can even bounce data P2P, from one client terminal to another.
Microsoft was talking about submarine data centers powered by tidal forces in the early 2000s.
There have been talks of data centers on Sealand-like nation states.
Geothermal ...
Exotic data center builds will always be hyped. Always be within the realm of feasibility when cost is no object, but probably outside of practicality or need.
Next it'll be fusion-powered data centers.
https://cfs.energy/news-and-media/commonwealth-fusion-system...