I’m not saying they’re not vapour, but the article does mention a series of closed door demos and thousands of GPUs deployed, so it at least appears that someone has seen something.
Different product categories, same vaporware/hype train potential. How good would the autocomplete demo have to be for someone to convince the unsophisticated to hand over $500M (based on a preponderance of the historical evidence)? That's the thesis. Not disbelieving the potential of the technology (considering Gemini 1.5 and Sora recently), but you're going to have to be fairly sophisticated to know the difference between what is real, what is show, and if it's going to have legs to carry a valuation vs being a flash in the pan.
(have done technical due diligence for M&A, but also realize a greater fool can be found; ask lots of questions, and ensure the people you're trusting to validate the responses to those questions have the necessary domain expertise)