The Warriors are very likely to lose Iggy, and possibly also Livingston and Zaza.
They will need to renounce just about everyone if they are going to give Durant a max deal.
Once KD opts out, they Warriors will technically only have ~$37M worth of players under contract.
With a $101M salary cap that seems manageable... But to get Durant a full $35M max they need to get their cap # down to $66M.
However Curry will need to be resigned, and his cap hold will be $18M. Iggy's hold will be $17M, and Livingston's will be $11M. Zaza's will be $3M. Add to that a few extra mill in cap holds for minimum salary roster spots and you're at ~$88M, and that assumes everyone else with an expiring is renounced.
Even if KD agrees to a lesser contract of, say, $30M per season, the Warriors would still need to shed $17M in cap holds - which is exactly the amount of Iggy's cap hold.
If they renounce they lose his bird rights and he's a goner for sure.
Zaza will likely command good money next year after his surprisingly productive season, and Livingston is due a big payday as well.
Of the three, IMO Livingston is the most likely to be back, but it's no certainty. And he is also 31, and is due for a decline.
Their bench is going to be running on fumes before long.