I think you're right, but If he were to be traded, I'd wager it's because he made it known his intentions to not sign an extension here, rather than for lack of performance issues like with Claypool.
Yes he's a lazy route runner and isn't near polished or matured, but the potential is obvious. He knows as well as anybody what his ceiling could be if he was instead developing as the primary receiver being thrown the ball by a top QB instead of one in the bottom third of the league who's hamstrung even further by a head coach who enforces a conservative style of offense. If he's not already, he'll be looking for greener pastures sooner rather than later.
Normally I'd expect them to keep him until he walks in free agency as the Steelers usual m.o. is to maintain that .500 record streak at all costs. But the trading of Claypool might be a sign of things modernizing ever so slightly in the front office regarding expiring assets that could provide more value as a draft pick(s) than their contribution to a meaningless streak.
Regardless of how it happens, I don't see him sticking around long enough to be part of the next winning core. Too much money to be made elsewhere.