Even for something like an emergency stay, where you are still mobile, but shouldn't fly, I was told by the immigration person herself that it would be easier just to arrange a border run, as there is quite a lot that both you and the hospital have to do to extend for medical reasons in country. Think Marriage visa like stuff. Proof of this, proof of that...
(I was just getting a regular extension, but it came up in conversation with her.)
It is all speculation, but speculation comes from bits of truth. There are also reports that there is a start and end date to the change. We should know the full details on Tuesday.
Flights all the time. I went to Cambodia in November. Leaving BKK, they asked me if I had a departure flight from Cambodia. Departing Cambodia, they asked if I had a departing flight from Thailand. They seem to be ramping up this part for sure.