Misleading headline there.
Ranong seems to be issuing stamps as normal and there have been no reports of problems at Surin and Sisaket border checkpoints, despite being on the Thai-Cambodian border.
It appears this ‘crackdown’ or sudden change of policy only affects those border checkpoints in the central region which fall under the jurisdiction of Immigration Division 3. These border checkpoints are also the closest crossings from Bangkok and the Eastern Seaboard - areas where there are large numbers of migrant workers from Laos, Vietnam, Cambodia and Myanmar.