I don't think they are hoping Tebow fails. I think that they decided to go into rebuilding mode.
They have depth at the receiver position and Llyod doesn't look like he will be resigning at the end of the year therefore they went out and got something for him instead of losing him for nothing.
Tebow still have E. Decker & Thomas and Royal (until he is traded).
If Tebow is the real deal, he should still be able to produce with those two receivers... if not... Luck at number 1 wouldn't be the worst back up plan.