What you're describing is an offseason move,TDL moves have been expiring contracts going one way and picks coming back.Because every playoff team is max capped or close to it.
If a playoff team needs cap space to get a guy they think will put them over the top, they will give up assets for the cap space.
My point is,why would a team give up it's first to save a few months worth of salary?
We see players go this TDL almost every year,we gave up a 1st for Ladd,the Jets gave up a 1st for Stasny and then again for Hayes and many more.
I'm not saying the Hawks shouldn't or wouldn't pick up a contract to get a 1st back but it sure as hell won't be an expiring contract and the player involved probably won't be much either.........possibly bought out.