That's huge IF, both of them have 90 day exit clause, and it's not like it's a long-term business.
Those deals are doable because xAI failed and SpaceX has a bunch of spare compute lying around they can rent out. However, SpaceX doesn't make the hardware or software so moat is nonexistent.
If compute capacity increases or AI demand decreases, Google/Anthropic will likely skip SpaceX and just buy their own hardware in their own datacenters or go back to their own datacenters.
I think anthropic needs that compute. They'll probably rent it as long as they can. They aren't really in the datacenter business. Google yes, I think they'll stop at some point.