The only downside I could see is if his salary is high enough to be included in the compensatory pick calculation (which could wipe out a potential 4th rounder for Adebo). If so, wish they would have waited until after the draft to sign.
It's a one year deal for a below average player, I don't think his salary will make much of an impact. Plus, you have to add to the free agent losses and additions the Lucas Patrick signing, which wasn't on the books before.