If anything, r1 makes even more GPU demand likely, since it mitigated or at least delayed the risk AI hit a dead end (in which case, ceasing development may actually make sense).
Unless AI is a bubble, and it pops, I can't see the demand for compute going down.
Project Stargate is some large fraction of that, and of course Softbank is no stranger to losing money on overestimating demand (for example, WeWork). To be fair, China has a lot of overestimation of demand too (for example Evergrande). The other is that rapid competition leads to overinvestment by all parties.
https://www.wsj.com/tech/ai/sam-altman-seeks-trillions-of-do...
And money 5 years from now is simply worth less to markets than money 7 years from now.