So I sat down and read it and...
Well...wat?
The Tsaeci are Goa'uld CHIMsters? They're of alien intelligence and serpentine in nature, but they keep talking about having bodies prepared for them and how many of their race suffered a burnout that reminded me of Zero Summing. So I'm assuming the serpentine quality isn't completely apparent because they've never been shown as snake people, plus the creation myth revolves heavily around "eating" in a metaphorical sense.
So what I really want to ask is: Is this just some obscure bit of Lore that was pulled from the Imperial Library site or did it actually exist somewhere in a previous Elder Scrolls game? If it's supplemental material not actually existing "In Game" somewhere, I'm not going to dwell heavily on it, but if it's a relic from a physical book somewhere in the TES universe, then that means I'll be devoting a lot more time to chewing on the idea that the Tsaeci are a Franchise Hopping Extra-Planetary species that have all attained CHIM.