Hi Steve, no the customs will not be closed. Based on the latest reports, food and cargo will still be allowed to pass through customs. However, Malaysians are barred from leaving and foreigners barred from entering Malaysia during the two week period (starting 18 March). Please refer to this article for more details regarding this travel restriction https://www.motorist.sg/article/554/malaysia-travel-restriction-everything-you-need-to-know.