First: Of course they could be all made up. In these days there are many lies about much more serious and obvious subjects. We have a war on information about almost everything.

It‘s as BinSabai said. It depends on different factors, where you end up after tested positive. If your Thai contacts are as bad as possible and you are as incapable as possible, then you will end up in the worst scenario possible, which is staying in a expensive hospital for 10 days. In some countries of the world some people get their pride from being as dumb as possible. Thailand doesn‘t belong to that kind of countries.

The most important advice is to manage your situation as much as possible actively by yourself if you are tested positive. Most people, who end up in a hospital without having symptoms, did nothing but waiting and after 1-3 days of them doing nothing, the Thai authorities took their actions. If you have any kind of personal contacts to Thai people (including hotel management staff as i.e. a frequent guest) use them. And if your are talking to an official face-to-face try to get dressed in an appropriate way before. Even if the pre departure is scrapped, get tested before departure. Traveling to Thailand from a country with a high rate of infections without being sure of being negative belongs to the most stupid things someone can do.

Very soon that will be history anyway as all restrictions will be scrapped starting from June or July. That‘s in two or three months.