That border is mostly used by visarun agencies, carrying expats to get 90 days stamp (if have legal visa) or 30 days stamp (if don't have). Now this second category is no more allowed to get 30 days stamp.
I suppose this rule doesn't affect Malaysian Citizens.
Sorry, probably I didn't explain well: any expats living in Thailand who will cross the border in Satun, when re-enter in Thailand (Satun border) will be refused to get 30 days stamps.
If they have legal visa, no problem to get 90 days stamp.