"I agree that others are involved, but ultimately Lara Spencer has the most visible agency here ... and power. No doubt she could have influenced the language used in that segment and most definitely the tone in which she read the copy. She could have changed either and did not."
You've got it exactly right. Spencer could have listed ballet as one of the things that the young prince would be involved in, but NOT saved it for last in the list as a punch line, not made a face after she said it, and not followwed up with the stupid and nervy comment "We'll see how long that lasts."
One of the other things Spencer mentioned on the list was "computer programming." Why didn't she stop after THAT, make a face, and then say "We'll see how long that lasts? Because, in her mind, computer programming is completely "acceptable" for a boy to study, but ballet is not.
And yes, it's true that one point of the "report" was to note that George is going to have a very full schedule as a very young child, but that ended up coming off as secondary to the need to make fun of the fact that he's going to be studying ballet.