Yes, rights return to Toho. That's what happened to the Showa movies I mentioned above. Nothing is stopping Sony from picking up the rights except that they choose not to re-obtain the rights. They did it once for the 50th anniversary and didn't feel like hanging onto the rights, for whatever reason.

I'm hoping that with the new movie next year, and it being the 60th anniversary, someone is going to go, 'Hey, let's license as many as we can." And hopefully, it will be someone awesome like Shout Factory or Criterion.

Okay, a pipe dream, but I'd love it is Criterion would tackle a few more Godzilla movies.

Oh. That's unfortunate. I thought from your initial post that other companies held the rights and they're just sitting on them.
Man, I hope the new movie renews interest and someone gets interested in releasing the other movies...

I'd love for that, too. Those are just awesome releases!