In this case I think it's more than self promotion and shit stirring. He knows the future of red bull after Max isn't in a Formula 1 car, and that's kind of his job to take care of.
Checo is doing Checo things, forever trying to replicate his last to first drive.
Danny is more of a supersub driver than a prospect driver at this point. It's pitiful, but it is what it is.
Yuki shows flashes of brilliant driving but just can't seem to impress anyone at Red Bull enough to be considered for the main team.
That leaves basically no one besides the academy drivers, and I think the point he's making is it doesn't make a lot of sense to tread water with 'average' drivers when you could be developing someone else with a higher ceiling.
That's a great tip!