Eh, I think it's time to let go. Even if he did make a team, odds are stacked against him to become fantasy relevant for the foreseeable future. Dropping him for a kicker's painful, but if you're in need... you gotta do whatchu gotta do.
Why he isn't on a NFL team right now, I don't know why. I want to pick him up in my league and drop Hixon, but what is the point until a team signs him. He finally played well last year, lead his teams in catches, is a tall red zone wr. Why isn't St. Louis calling, Chicago, Detroit, NY Jets, Oakland, San Fran, Miami, Cleveland, Houston, K.C., Dallas, Carolina and Tampa Bay, just to name a few teams that could use some help. I would say if he isn't signed by now drop him and keep and eye on him and see if he is signed. Good luck.
You've gotta bite the bullet and drop him, Tenn seemed like his last chance in the foreseeable future, and even if he does eventually get signed he won't be up to productive shape for a while. Fill the spot with a need that can start producing points now.