Lets try this as per code --
400.8 Uses Not Permitted
Unless specifically permitted in 400.7, flexible cords and cables shall not be used for the following: in which we find --
(2) Where run through holes in walls, structural ceilings, suspended ceilings, dropped ceilings, or floors -- Got it.
Now I am going to show specifically permitted --
400.7 Uses Permitted
(A) Uses . Flexible cords and cables shall be used only for the following:
(8) Appliances where the fastening means and mechanical connections are specifically designed to permit ready removal for maintenance and repair, and the appliance is intended or identified for flexible cord connection.
Point in case for arguement
(A)Types NM, NMC, and NMS. Types NM, NMC, and NMS cables shall not be permitted as follows
(2) Exposed in dropped or suspended ceilings in other than one- and two-family and multifamily dwellings -- The reason I threw this in was to point out the difference commentary explains for a drop ceiling when access is available is the case of using NM. When no access is available NM is not restricted in use for the "other than".
IMHO The same should be considered when 400.7(A)(8) specifically permts the use of cords for appliances having access an proper listings.