Dude of course some of them will be version exclusives. LOL
Aside the obvious Spewpa line, Talonflame line staying along a few others, I can see the Aromatisse line, Swirlix line and more, at least over 70 Pokemon, cannot be found in Z.
That happened between RS and Em, Roserade and Meditite are no where to be found in Emerald. While Misdreavus and Murkrow are unavailable in Platinum, whilst they are exclusive in Pearl and Diamond before HGSS' release.