Personally, i doubt they will receive Major Overhauls.
I feel Part 2 Races feel way more complete than Part 1 Races. Skaven were the only Race that was severely lacking and their Under Empire Overhaul truly brought them up.
The Lizardmen could need some tweaks here and there, and that is mostly to units that needs some buffs to their stats.
Even with their Overhauls, i still feel Empire and Dwarfs have room for improvement.
Vampires are fine where they are. We just need more LLs.
Greenskins will get their Overhaul. Hard to judge if they will need more tweaking. But we need more Generic Lord variety for them. This one is key.
If anything Part 3 looks like it will be more Overhauls to Part 1 Races, but these Overhauls will also cover the DLC Races (Chaos, Beastmen, Wood Elves and Norsca)
I am almost sure that the Empire will get a 2nd Overhaul. Specially if other Elector Counts are made playable.
Just as the Empire got Fort Sieges. I feel the Dwarfs may get Karak Sieges. Truly bringing out their full potential.
Chaos and Beastmen are the 2 Races that need an Overhaul the most. Being the first pieces of DLC has really made them lag behind in terms of quality with newer DLC.
Wood Elves Overhaul is not as massive as Chaos or Beastmen. But we definitely need more LLs at least.
As for Norsca. Their Monstrous Arcanum needs to be updated and add some Tomb Kings, Vampire Coast, Lizardmen Dread Saurian Hunts. And once Daemons are properly added. Overhaul the Rewards for worshipping a certain god.