All have obtained important junior prizes and big permanent positions recently, published several papers in JAMS & Ann. Math. since 2006, and finally they are into their last cycle of eligibility (except Avila). Plus it’s a good mix of subjects.
Then, Nevanlinna: Irit Dinur ; Gauss: Yves Meyer ; Chern: Louis Nirenberg. Again, just an educated guess, at least the full participant list so far says they will be there, and they look like good bets (if I understood the prize descriptions correctly).
According to the latest schedule, the opening ceremony (which will be streamed live) is set for 9:30 to 12:30am local time, that’s UTC/GMT +5:30. So something like thursday 19 august at 10:30am in Hyderabad will translate into 7:00am Paris time, 6:00am London time, 1:00am East Coast time and actually wednesday 18 august 10:00pm West Coast time. Thus Europe and the Americas will definitely be awake when it’s announced, convenient.
But before that, the Perseids!