Salas and Nelson are there (although he is hurt) then you will have the backups in Walter Powell, Owusu, Hakim and TJ Graham.
Judging his draft profile he seems like a smart heady player who runs good routes, has good speed and can return kicks at a very efficient rate. He suffered 3 concussions in a 13 month span which crushed his draft stock. Not to say this guy will light the world on fire but it's worth taking a bottom of the roster flyer on a guy like this.
It's common. You always shuffle the bottom of the roster around looking for players that will impress and hopefully stick. It rarely has a negative impact and can help find those diamonds in the rough. Not that that's what's happening, but you never know.
Also the scouting staff. They have how long to evaluate talent? Out of those 12 picks I wonder how many will make the roster next season, really not good enough.