Those explanations in themselves are bound to be damaging, aren't they? How do you tell a child that both his grandfathers (and uncles, aunts and cousins) are such awful people (racists etc) that they've had to be cut off?
And their family aren't just anyone.
One day, if they haven't already, Archie and Lili are going to ask why they are a Prince and Princess. They will be told that they are grandchildren of a King, but are being kept away from him and the rest of the family because they are so horrid. They'll still use the titles however. I wonder if one day they'll look at their cousins and resent the fact that they have not been allowed to enjoy their unique heritage.
And it's not like they have relations with most of Meghan's family either.
Oh well, a retired tennis player the kids see briefly maybe once or twice a year is an 'auntie'.