So is Vortex/Continuum/Fire/Air all frozen in time, or is that just Gaudiguch/Hallifax?

Gaudiguch-Fire-Vortex and Hallifax-Air-Continuum are all "Lost in Time"

There's no reason a plane opening has to lead to everything appearing, or that the cities appearing has to lead to them being player-run. Glomdoring was around for a long time before an event came up that let players live there.

While I don't think it's necessarily needed right now, theoretically the planes of fire and air could be created and opened via quests or something, without any need for the cities to be released. Or the ruins or reflections or something of the city could be released, waiting for an event much later in time before the cities are actually open.

Maybe we could enter it, only we would only see frozen images...that would be cool...like mid-battle and stuff

The "reflections" are already there. We just can't access them. Some sort of time barrier. And tehre is every reason the plane opening would bring back the rest. They are all trapped within one big time spell, so if one comes, the other would. Also, the Nexii act like big foundation-tower thingies. One goes down, the rest does. One comes back, it pulls the rest out.

Yeah, but Glom was never lost in time. The nexus was just blasted into insanly negative power. Ackleberry is lost in time, or hidden in time or whatever Bear and Lake did, and you can't get to its ethereal version.

Ackleberry has been sundered from all the planes, according to the Moon Priestess of the time.