Even if the AI bubble pops spectacularly and Microsoft aren’t training any new models in two years, Microsoft still have massive datacentres that need to compute loads of things, and loads of things they’d like to compute, but don’t because they don’t have the capacity, but might end up doing if they’re suddenly not training AI models on lots of machines. Having free electricity for twenty years is useful for a tech company with or without AI, and nuclear is a good way to get back on track for being carbon neutral soonish like they were going to be before all the recent AI stuff.