It's based off that 30% of code written by AI quote from the MS CEO last year.

https://www.cnbc.com/2025/04/29/satya-nadella-says-as-much-a...

Note that he said written by, not assisted; and also that there's been some major QA issues with win11 the last year, enough for Microsoft to have made a public apology/commitment to improve...

So, no definitive evidence, but the rest of the breadcrumbs provide enough to say that yes it does appear to have suffered from it.

Given the Debian policy seems more geared towards aided/assisted an existing dev than replacing them and shipping because the code works on the golden path on a devs monster pc ... Well I'd still keep an eye on it but trust OSS OS engineers to have some competence at knowing if this works and adjusting the policy later if it proved to be wrong.