Here is GHB2018 review from BoLS channel
In short:
- Masters of order now give +6 range on roll of 10+ instead of doubles;
- Masters of space and time results changed a bit (unit does nothing on 1-2, but can move on 5-6);
- Arcane might gives one cast and unbind reroll every hero phase;
- Disciplined Fury gives rerolls of 1's for general;
- Mighty War leader gives +1 CP in every hero phase on 5+;
- IR heals d6 wounds instead of d3;
- Prism of Amyntok deals d6 MW instead of d3 if roll was 6;
- Engine of Gods summons either 20 skinks, or 10 warriors, or 3 ripperdactyl\terradon for free on 14-17 result;
- Fangs of Sotek First Oldblood ability gives +1 CP;
- Wordings of Dracothion's Tail changed a bit, but effects are pretty much the same, I guess;
- Summoning cost: 6 points - Salamander, Razordon, 10 skinks, handlers, 12 points - terradons, ripperdactyls, starpriest, priest, 10 warriors, sunblood, oldblood, 5 chama skinks, warden, 10 guard, 10 knights, scarvet on CO, 18 points - troglodon, starseer, astrolith, EotG, 3 Kroxigor, 20 Warriors, 24 points - stegadon, bastiladon, both carnos;
- no summoning restrictions in matched play - I didn't notice any at least.
May have forgotten something - you can check everything for yourself.