I would think a 2nd round WR would get a lot of reps in his 1st Training Camp to see what he can do. If he doesn’t show much, he probably drops down in the pecking order if another WR is looking better than him.
In his 3 years with Arizona, I would expect the coaching staff wanted to see significant improvement at the start of each successive training camp. If he didn’t show much, he probably got less reps than he did the prior year. As time goes by, the patience you mentioned decreases.
After 3 years, the Arizona coaches may have determined that, not only isn’t he meeting the expectations of a 2nd round pick, he’s not good enough to keep on the roster.
A change of scenery should set the clocks back for expectations and patience but he really needs to stand out to be more than just training camp fodder.