I disagree on this approach because people end up hitting upwards instead of forward
I think there is some good reasoning behind training that stroke first though, it's a lot easier to change the trajectory of your swing than to change to nature of the way your stroke contacts the ball.
By encouraging the upward stroke with a finer contact, you get a higher quality ball once you get faster blades/rubbers and change the angle of your stroke a bit.
Whereas you can learn to play TT perfectly fine with a flatter contact (still getting some topspin), and this will be the natural way kids are likely to play their stroke without a bit of outside influence since it's a much lower effort shot for the same speed, but once you scale that up you end up with a much lower 'quality' stroke, eg with less spin.
Since the mentality for kids' training tends to be to give them solid mechanics, it makes a lot of sense to train them to be able to play the higher quality, high spin, brushing, stroke first.