I am also in the same situation with Foxhall/ Dr. Green. TBH I was more than happy to pay OON costs to ensure I would see the same person throughout and am having a hard time finding another practice that offers the same "concierge" service.
I did come across this article re: Sibley and a Women's Center generally from 2022. Maybe Foxhall found it would be more lucrative to pivot to GYN at Sibley since these are the types of services they're switching to?
https://www.washingtonpost.com/magazine/2022/09/07/womens-center-sibley-hospital/
I did ask one of the non- partner (non-owner) OB's if there was a lawsuit that made their insurance prohibitively high after a certain date and she said no. It sounds like most of the docs that were still doing OB were non-partners, and it was a partner doc decision to stop since a majority were no longer interested in doing OB. The non-partner doc even mentioned she found out about the change in a very similar manner to the patents with a letter and not much time to figure out a change