The information in the lore is not that detailed.
I'm not sure if the channelers are supposed to be something new that just recently popped, or an ability that always existed but for some reason never used.
But it does mention two things about the ability to channel magic: that it's a rare ability, and that it is the power that might restore the world.
The part about being rare is implemented nicely in the game. It requires children or a special magic to have other units with the ability to cast spells.
As for the "use magic to restore the world", it is only done by using the sovereign to create the first city. Hardly enough if they want to stick to the lore of the game, and I think it can be a great thing if they do since it creates a new concept and since it can be implemented in many different good ways.