Yeah, I was wondering that too. So you show up on April 1 and they say you cannot get an extention because you have been in Thailand to long with the Amnesty . And they will fine you 500 Baht a day until you can get a flight out. Which will probably still be cancelled if you can find one at all.
I have insurrance that covers inpatient only. It includes Dengue and Covid-19 but I don't want to recommend them because I have never had to use them.
But when you start searching for Expat Insurrance they will be one of the first to pop up. They are not one of the huge companies and their reviews are mostly positive. But they will NOT, under any circumstances, cover pre-existing conditions.
That seems to be the biggest issue people have with them.
But it gets me across the borders and I am pretty sure it will get me in the doors of a hospital.
You also need a Health Certificate saying you are Covid-19 free within 72 hours of arrival. And pay ~$162 for testing after you arrive including 24 hour waiting with your group and 3 meals. If anyone in your group tests positive, then you are in for a 14 day guaranteen (What the $3000 Deposit is for).
I don't think the $3000 is scrapped but some reports are saying they are not asking for it. But you should have it ready.
Also, I hear they are not issuing new visas. So you can try the Cambodian Embassy but you may be out of luck. Pretty sure Visa on Arrival is suspended.
But good luck finding a flight in. And I believe All land crossing are only open to business traffic.