It seems like the Steelers are trying to get back some of what they apparently wasted on Boykin and Scobee.
With that being said, Thomas is kind of an odd player to "put on the block," given how he hasn't shown much at all.
However, the kid is an explosive athete who showed great instincts in college and flashed some man coverage skills early in his rookie year.
Maybe they know there is some interest out there from teams who implement simpler schemes where he can just read in react and not have to consider and adjust to like a million variables every play, like the Steelers ask from their safeties.