That story is data governance. Corporate already have a data-agreement with MS, storing all their data there. Github copilot is covered by that, while a individual agreement with e.g. anthropic needs lawers involved.

It’s precisely this, and, to be fair, it’s a rational approach given a Data Security Exhibit starts at 6 weeks and can hit 6 months to complete. That being said, I work with regulated data, so YMMV.

Can confirm, this is the situation.

Microsoft is simply the default answer for most large corporations. Getting access to some Microsoft subscription is very easy, because of the existing framework agreements, Microsoft providing any and all compliance slopuments needed and already being pre-cleared for corporate data etc. Meanwhile trying to use another provider (e.g. Anthropic) would be a one year endeavor, minimum.