I don't believe this to be true. It certainly has not been my experience, although I am yet to be vaccinated.
I have a work permit, yellow book and the pink Thai ID card.
I tick at least 2 of the boxes of the more vulnerable amongst us.
I have had my details taken by the village health volunteers and by my employer at least 1 month ago.
I am still waiting, but that is true for most if not all the inhabitants of my village and most of the employees of the company I work for, who are mostly Thai
I am aware of a number of expats having received vaccinations.
My feeling is that the problem is more one of insufficient vaccine doses to go around and expats not always wishing to receive the vaccine on offer.
More are being directed to areas where the problem is more acute. I am happy with that, although this is a problem which could have been foreseen and resolved much earlier.
I will be patient