According to the release notes for Black Hole version 2.0, it doesn't support images not in flash? So Meoboot can no longer be used, is that really so?

No, black hole is only supported if installed in flash.
But you can use it in Meoboot, and other images to.
But they will not fix you problems that could occur if black hole is used with meoboot instead of in flash. But normally it will all work fine.