I'm fairly certain that Shapovalov has said he won't play juniors at all next year, and that Kecmanovic's push is in part because he doesn't intend to either. de Minaur seems to have stopped with the USO and, having reached the finals of a Challenger, doesn't seem as if he's likely to play juniors again ... though he didn't get any GSs so could, I suppose, go for those. FAA has his Grand Slam, and having made his point, also hasn't played juniors at all since. He's so young that he might still dip in and out ... but he's already winning Futures. So I think there's more likely to be - as there was this year - an opening for those below, as Oakland suggests.

For what it's worth, the ATP ranking of the 1998s and younger who were top 10 last year and went towards the ATP this year, though still eligible to play as juniors, range hugely - from 230 for Casper Ruud to 997 for Mate Valkusz (the four - Blumberg hasn't played - average out at 591). The ATP rankings of the 1998s and younger who were top 20 two years ago and are no longer playing juniors (much), however, are much higher overall: 116 (Kozlov), 596 (Chung), 198 (Mmoh), 149 (Lee), 492 (Ymer), and a low of 667 for Luz. So yes, a push forward at 16/17 would be a good sign!