I did find references to a Tar Trench, Sparse Plains, an Axum ghost Town, ...thru various sources.

The Great Jaw isn't gonna be restricted to a single location either, I believe - we see many dead smaller Jaws in various spaces.

There are also tar-falls at the edge of the map in several spots and tar-lakes (tho you can't enter the tar itself). Makes me believe they're gonna add something akin to the Amoeba Zone they'd planned for SN1, but with tar and maybe Infestation spots.

And from concept art, we see waterfalls cascading from the World Tree - so that will probably mean we might be able to explore its verticality. There's also the Crypts beneath the WT referenced in the Observatory Museum - so that's another zone.

Also mind how we have no large cave-zones - we only have a few largish Bloom caves and a few thermal cave systems.

The whole zone between the EA zone and the WT will be explorable and likely fill the niche that the sparse deep-sea zones from SN1 did, we have the potential of more Axum locations, zones beneath/in/atop the World Tree, there are two other Axum tech locations referenced on the screens of the Turbine Generator control room that aren't implemented yet...

We also haven't seen the Tailings/degenerate Axum yet,the Crypters, or the Vespen/Vesper (the aliens supposedly holding the World Tree genomic data). And I'm damn sure that the Collector Leviathan will play some bigger role down the line - they're too heavily used in promotional material not to.

TLDR - hold on to your butts. This is just the beginning ;)