I believe the consensus is: it's a conspiracy theory. You only need to pick a museum-- the Metropolitan Museum, NY; The Brooklyn Museum; The Hearst Museum, UC Berkeley; The British Museum; The Louvre- all good options that have both Egyptian collections and have pictures of those collections online-- to see for yourself that many statues retain their noses and so to wall reliefs and paintings. I thought that the "Ancient Egyptian Race Controversy" article on rationalwiki.org (https://rationalwiki.org/wiki/Ancient_Egyptian_race_controversy) gave a good overview and listed a lot of sources you can go look up on your own.