Yes, there were supposed to be 3 novels. The last, The Rikti War, never came. Two different writers have been mentioned as attached to the book, so I'm not even sure if it was even ever written.
If a 3rd completed novel existed, I never found any traces of it internally. So it definitely never leaked. :-(
So then now that we've answered the better question can we go back to my initial question of whether anyone's read the first two and are they worth me getting physical copies of like some poo-slinging savage?
If you can get copies cheap, read them and then recycle them.
As to recycling, I was gonna replace all the character names with Popeye or Joey Lawrence as I read then mail them to Tahquitz.
The original book ran for 12 issues. You can see all the covers here:https://www.comics.org/series/13687/covers/I really enjoyed this run. The story doesn't exactly match the game lore but I'm good with that.