True, thanks for correcting me. Fox only distributed the Terrytoons. Fox never had an in-house animation studio during the Golden Age of Animation, though I think the only other cartoon that Fox distributed, (sorry if I'm off topic) was broadcast distribution of Filmation's version of The Hardy Boys, though who knows who owns that since it hasn't been seen in years and is not in Classic Media's catalog.
Back on topic, CBS bought the rights to the Terrytoons in the mid-50s, (Correct me if I'm wrong). So Disney never owned the Terrytoons in the first place because they are not part of Fox's catalog.