Thanks for reaching out. We don't have exact timing for the full transition or the Organizations structure yet but I have been told this will be happening within the next 6 months. At this time, we are fully supporting the Organizations model with several new endpoints as well as still supporting the legacy user owned event model. For now, we recommend all new development is done with the Organizations model and new create endpoints and that you have a transition to the Organizations model on your product roadmap.
The developer newsletter is being replaced with un-scheduled operational emails to update our partners on updates, deprecations, and feature/functionality changes as necessary. You will be seeing the first one over the next several weeks which will introduce a number of upcoming improvements to our API.