I don't know about speculation though i did spot some familiar landmarks in the trailer for 7.2 of the occult cresant assuming they weren't the originals. The pyramid from weeping city of mhach and what looks like moss covered towers from the floating city of nym. Don't know why they are there much less in the same place.

As for 7.2 and beyond if i were to speculate to be quite honest we could have by now gone to the "unlost world" supposed ninth shard use a bunch of electrope and create a massive amount water aether i believe to counter act the massive lightning aether on the ninth and send everyone home.

I also wish they would stop beating around the bush with these shades of the thirteenth. From the ninth floor of pandemonium's boss, to Zorral ja becoming a voidsent with all those souls, to now with arcadian, and solution nine's soul use. it is just everywhere. Stop teasing us.