Even the best teams in the league don't have a quality TE in their bottom 36 players. I can't think of a single team that is 3 or 4 deep in quality TE's. Most teams have 1, maybe 2. Those guys aren't cut unless they flat out can't play anymore.
Could they find someone better than Williams/Jones/Maneri? Possibly. Can they find a guy who is worth a roster spot? That's a different story, and given the depth of the roster elsewhere, I don't know that a slight upgrade from crap (Jones) to fringe talent at #3 TE is worth cutting a solid ST (e.g. Ebner, K.Davis, etc) or a developmental OL (e.g. Devey, Fleming, etc).
Given Develin's ability to play some TE, I don't think there's anyone who will hit the waiver wire who is worth bringing in.
Maybe they can find a raw-with-upside practice squad guy who is an upgrade on Jones.