Something we should know

I always assumed that the races depicted ruled the First City. That’s why the last two are blank. For at least one age, no one race has officially sat upon the Throne to rule the City.

How the makers of the art knew what races would appear in the future is a bigger mystery.
I thought something along those lines too, but then why would their be two undescribed spaces inbetween the Issori and the Ssethrics?

On presumably the first wall is a series of
undecipherable glyphs with a large [THIS DESCRIPTION HAS BEEN REPLACED WITH THE ISSORI AS WE KNOW THEM]
After that, each wall covers another strange
species but eventually you can recognize a Ssethregoran
Serpent Man, then an Elorii and finally a human being.
Ominously, the final [TWO] walls are blank, although the
borders and framing symbols all appear to be inscribed.
We have yet to decide whether this means that the
original scribes ran out of time to finish their work or
whether this foretells the end of all life upon Arcanis.

Octagonal room, with one side being the door, presumably.

Wall 1 – Issori
Wall 2 – Unknown?
Wall 3 – Ssethrics
Wall 4 – Elorii
Wall 5 – Humans
Wall 6 – BLANK
Wall 7 – BLANK
Wall 8 – Door?
I didn’t think about the door not having a picture on it. I read Issori as first. 2 blanks as the last 2. With that I came up with 2 undiscribed spots in between the Issori and Ssethrics.

Question, is there a second out of this room?