I doubt the Packers are in that big of a hurry to release Amari, after all, he has been paid for the season and there isn't anyone nipping at his heels to replace what he does. Once Watkins is back and if Toure is looking good in practices, if they can find a returner, then they might consider trading, releasing or putting Amari on the PS.
As far as waiting for him to blossom into an NFL WR, I might believe the Packers thought he was on his way to doing that, if he was actually seeing more offensive snaps. Injuries can change things fast on a roster and he could be needed later in the season.