OpenAI has over 1 million GPU.

Starlink satellites would be pointless for doing computation because they are spread across the Earth resulting in horrible latency. AI companies spend lots of money on super fast connects within a datacenter.

Starlink with GPU might have some advantage for running edge GPU. But most Starlink customers are close to ground station and it makes a lot more sense to have GPUs there. It is a lot easier to manage them than launching new satellites which could take years.