Equity in education isn't to see a kid that's doing well and think, "well fuck that kid, we'll just make him bored out of his mind and ultimately become disinterested as we force them to sit through another year of class on a subject they already mastered."
Rather, it's simply to redirect resources (read: money to hire more teachers so there's a smaller student to teacher ratio) to the schools whose students are achieving the least. And teachers are the ones that get to make that determination.
Of course I disagree with the proposal in the post, but I wonder... how much real encouragement did Newton, Euler and Einstein get (or need) when they were young? Could anybody have stood in their way? Ramanujan got as little encouragement as one could imagine but still ended up as one of the greatest mathematicians of his time - but on the other hand, maybe he would have been even greater if he had had more opportunities.
And that's not just a proposal from some rando, it's a DoE policy. It seems to be an ideological trends of destroying advanced education so that "equity" ideologies can feel good about it.