Actually what was said is they wish they would’ve made the entire game that way, but it’s too late now. So Sirrian said they’d like to make a new game mode where only 1 of a troop would be allowed. The change wouldn’t effect how the game is now.
So yeah it stacks, and will continue to stack.
Here’s what I mean. This was in response to someone asking if they can place the 1 troop/trait restriction now in the current game.