The latest development update is now live on the MS Flight Simulator website: https://www.flightsimulator.com/july...opment-update/

There is a good amount of information concerning 3rd party development.

If you are signed-up as an FS Insider, there is also a new Development Roadmap in the Insider Home which takes us through the end of September, with indication of the next development roadmap being released in mid-September. Along with continued development and testing of the SDK through September, and release of more Partnership Series, the roadmap also indicates the Feedback Snapshot reports that will continue to be released on a regular basis following launch. As the Development Roadmap also indicates, a Beta Preview was released to testers today, with the Beta still on track for release on July 30th ahead of the launch date of August 18th.