It may be as simple, as just releasing to developers, read ability to the Internal Update Information that Asobo are making to MSFS,.
The level of detail in the currently release Update Information, is all but useless to Developers, and appears to be more something put together by Marketing, to promote that MSFS is being actively updated.
I would expect more like 20+ pages of detailed update info, for it to be of any meaningful use to 3rd party developers.
ie
Mostly Sales Info – very little technical content about what is being changed, and for what is mentioned, little or no meaningful details.