Some comments on each:
Gurley- the Rams will (or will not) pick up his 5th year option in 2019- which is over $9.1M- based on his 2017. So yes, somewhat of a prove it year.
Austin- structure of his contract extension allows them to part ways easily after 2017. So yes.
Robinson- move on already....
Higbee- didn't live up to the training camp hype. But also keep in mind he was 2nd in targets this year among rookie TEs (29) and tied for 6th in receptions (11). Only three rookie TEs had even 19+ catches. Henry and Hooper made the biggest splashes. Just saying Higbee isn't as far away as some might think. And given how much McVay liked using TEs in DC Higbee may be one of his big projects.