Err, that's right of course, but one would expect that a person who studied history of arts would know that the original Fabergé eggs aren't produced anymore. I mean, it doesn't really need a study to know that either way. Quite a faux pas, IMO.
Well, with such things you never know... Catherine wore a Cartier tiara from the 1930s at her wedding but she could still order a one new tomorrow. As it is still a member of the Fabergé-family who creates under the family name, I'd guess it's not so easy a question. Depends on your POV but if Catherine decided tomorrow to invest a hefty sum of money and ordered a new "Royal" Fabergé Easter Egg to give to the queen for her Diamond Jubile Easter and Ms. Fabergé would use all her artistical skills, now wouldn't that be a "real" Royal Fabergé Egg, then?