Sorta correct. There are a few border crossing with immigration offices that could issue a reentry permit.
Suggest folk don't rely on that and better to obtain permit at their local immigration office.
Here is cut and paste from @BritTim
"Usually, you can only get a re-entry permit at the immigration office that issued your most recent extension, or at the airport on the day of departure. A few immigration offices located close to selected land crossings will issue you re-entry permits on the basis that you are on your way to cross over, leaving Thailand. If planning to leave by land, indicate the crossing you want to use and someone may be able to suggest where you can get a re-entry permit."