As already pointed out, the page numbers we've already seen rule thus out (and don't forget there will be a whole yuan-ti section after the orc section, so even more of the available pages will be used up with that). I imagine that we'll have 130 stat blocks for 96 monster entries, with several entries getting several variants.
I assumed that variants counted towards tge say 96 monsters, not groups of same type monsters counting as 1 monster towards the 96 count, but you could be right, especially after seeing tge Kobold Dragonshields. Oh well it was a nice theory while it lasted. Its still 1 of three chapters so there is likely to be alot of races in it, beyond the 8 we already know for sure are in it.