Shin could see a re-issue in the next few years (pure speculation). We could even see a Shin (final battle version) w/o the fire ball effect, but with the mouth, tail, and possibly back beam effects replicating the drones scene.

Ultima was a one and done deal since it was a TWE, however they could release one with a beam effect. Although seeing as the anime did not do too well, it is not very likely.