All these maps are not all-new. Didn't you read the description of what they were?
They are basically remastered classics, most of them have been part of early level design contest for Unreal that was held in 1998.
Then with a certain release of Unreal in France they included that extra CD (kind of a waste given it contained very little),
which had the "votlan" level in it, back in the vortex rikers. (plus it told you to get extra levels most of which were those contest entries so all those kinda made it a level pack,
this was after all an attempt to fix up such level pack and tie it together with a more coherent story)
The CD level was part based on a pre-release vortex2 with a new area/room. This area has been redesigned in this version to make it more beliavable as that level was obviously rushed and not tested properly, as if you walked towards the electrocution chair in the original, a bsp hole would crater you....
The intermissions etc are new, but as for the outro flyby.
That was actually made out of .the ut beta dm liandri (hence why it's not playable but this map might get playable in a sequel/addon as a sp map still) and some discarded brushes from the other maps/unused things. So there's that.
Yes I had a plan making an addon pack for this and I want to keep the details secret. Some preliminary work was done though. So this "story" is not yet fully done.
EDIT: You know I realize it is kind of funny that ONP made a big deal of returning back to Vortex Rikers when exactly the same premise was already in votlan and Unreal PSX.
Each having their take on it to boot too.
But thanks to the pack featuring now the early botpack stuff (why not, since it's all from a similar time), now we could have the transloc way done yet again in the inter map, which features the iconic room from gateway.unr by Shane Caudle.
Long ago when I was about 12 I kept dreaming that Vortex could have a side room somewhere with one of those devices from gateway or similar and back then I was also into Stargate a lot so now when we got to make this pack I recalled that old idea.