By a countertop shop in my town. I walked out on the guy and went to a quality shop.
The only reason to do this would be if the counter top is so long that a standard length laminate won't reach the entire length. Then to avoid a seam in the middle somewhere, the two small seams are a compromise. If this has to be done, have them fabricate that part of the top without particle board, and make sure the seams are completely sealed before the sink is installed.