I found whenever I looked at the iMacs with screens pulled off it had a glossy screen underneath (which was also pretty unevenly coated).
The only thing glossy about Apple's displays is the glass in front of the LCD. The LCD itself is matte, just like every other LCD on the planet that doesn't have something in front of it. If the glass is removed, you are left with a matte surface LCD.
Yes, Museum glass would be better than glossy glass. We use multi coated glasses on our camera lenses, and to frame prints - why not complete the loop and do the same with the workstation? I'd just be happy without any glass.