Here are some things about matte displays that I've learned after reviewing countless pen displays and tablets over the years (on my
blog and on
youtube)
1. Matte screen protectors have a tendency to expand the diffused light to a much larger area. E.g. When used outdoors with bright lighting, the whole display may just be white. This is the reason why I stopped using matte screen protectors because I use the tablet outdoors often.
2. From photos I've seen, it looks like Apple is trying to replicate the surface of matte textured LCD displays. My ordered nano-texture iPad Pro is not here yet so I can't say much more.
3. Matte screen protectors can have varying degrees of smoothness or roughness. The smoother ones will not degrade the visual quality as much, but they won't have the tactile drawing experience. The rougher ones will feel nice to draw/write with, but they will add grain and colour noise to the display.
ALL matte screen protectors will add grain and colour noise (or rainbow effect) to the display, it's just a matter of how much.
4. The nano-textured display can be probably be cleaned by non-Apple micro fiber cleaning cloth. People are not gonna read the instructions that says to use the Apple cleaning cloth. Human behaviour will tell people to use any micro-fiber cloth they have, or wipe it with their t-shirt.
5. Regarding the anti-glare. You will seen many people show reflections on the glossy display in Youtube videos. In the real world, the display will be facing your face which does not emit light. Most of reflections will likely come from lights behind you, not from above, unless you're outdoors.
6. Apple's anti-reflective coating is very effective. Together with the increase OLED brightness, the light from the display should go through the reflection so you won't even see reflection of your face. This is already so even on iPad Pros with LCD.
7. To prevent the Apple Pencil tip from gliding too smoothly on the display, one can use a matte screen protector, or get a US$2 silicone pen tip from AliExpress.