There is more, but not much at this point. It's important to distinguish between sessions marked in the BN discography as "unissued" and those marked "rejected." Cuscuna has shown a willingness to reevaluate and often release those in the former category; those in the latter rarely, if ever, see the light of day.
One I can can think of is the Kenny Dorham/Grant Green session that a few people clamored for on the Blue Note board. Not sure if it was "rejected", though, or merely "unissued." The rejected Tyrone Washington "Train Wreck" session will probably never make it out while Cuscuna is still running the show.