We prefer to not get very technical, but there are quite a few more factors that happen when you start to scout a province. So, besides the mana, there are a few more aspects that are interconnected with the activation of a scout.
Also, negative pop/culture does not touch as many mechanics as scouting does. Furthermore, if you have negative mana, decay needs to be rethought for example.
But as
@herodite said above, it is something that the developers took note of. Right now they are working other aspects of the game as you all know. I'd say it's a "no" for now, but a "maybe" for the future