Claypool was another diva baby that they had soured on. In that final season he had been benched for an on the field incident with another player and then later famously celebrated a catch when the Steelers had no timeouts and he let the clock run out costing them a chance at a win. He got fried by the organization and fans for that. Steelers did sign Smith-Schuster to a 2nd contract, it was a one year deal. He got injured a missed a bulk of that season and despite coming back for the playoffs, the Steelers simply let him walk (where he then signed another one year deal with KC).
What's funny here is that this isn't he said, she said stuff here. Pickens antics have been out in the open. Steelers wanted him gone due to that and we obliged them.