Unless Ryles punches someone, he's safe. Even the old Parramatta board wouldn't have looked to pull the trigger on a first year coach and the current board is a lot more conservative and measured with their decision making now.
For me it's Benji & Payten who are most at risk, with Robbo & Webster being outside chances. Benji will be let go if the team is struggling halfway through the year (or if they finish the same or worse as last year), Payten is gone if it looks like he is going to be a yo-yo coach.
Robbo is unlikely to be let go this year, simply because there isn't an obvious coach out there for Politis to try and replace him with, and as for Webster, the Warriors have struggled to attract decent coaches for the club, so I don't see them rushing to pull the trigger either.