The tech tree considers civ effects only when you are playing as them in the game. If you view them from pre-match lobby, most civ bonusses are not considered. The same is true for Indian villager cost, goth infantry cost etc.
Nothing related to this was mentioned in the patch notes of that update.
On further inspection. When I view the tech tree from the lobby, costs in the tech tree remember the last game you have played. If I played a Chinese game that ended in Imperial Age, the next time I view tech-tree in the lobby, all technologies are 20% cheaper (irrespective of which civ I have currently selected).
Then if I play a game as Vietnamese, next time I view the tech-tree from the lobby, eco techs don’t have wood cost.
Note: These are forgotten if I quit and restart the game. Then it shows costs for a generic civilization.