If they scale from 25 then OMG, pretty much wrecked the game, CS are OTT but you can temper a game by removing the right ones, pillaging with the raid card would just be stupid and you know it. I hope to hell it does not work like this.
I'm quite sure the senior dev team (Beach + Shirk) said in the Sweden livestream that they looked at pillaging and thought it needed a boost, and that they wanting pillaging to be as strong throughout the game as it is at the start, where the science / culture yield equals about 1/4th of the a new tech / civic. Further, I believe they indicated that it will use the same scaling system as chopping to increase the pillage yield continually throughout the game.
When considering this, though, we also need to keep in mind that in the ancient era there are only a few improvements around to pillage. By the classical era, there are more improvements, some districts, and some Tier 1 buildings. By the medieval era, there's a lot more improvements, districts, and buildings.
In other words, the potential yields from pillaging already scales in the game, because the number of things to pillage scale. Scaling raw pillage yields with chops will now exponentially increase the potential gains from pillaging as the eras go on and the AI has a larger and larger infrastructure to raid.
If the AI is taught to pillage, this will make a peaceful Deity game more challenging, as the AI essentially colludes with itself to repair improvements for it's neighbours to pillage. This could potentially lead to the AI benefitting more from aggression that it does now.
In multi-player, it will presumably encourage aggressive play, as a war can pay for itself even if you're not able to capture an enemy city. I would guess it would be very difficult, if not impossible, to build an infrastructure in multi-player that could generate as much yield domestically as an aggressive player could generate from attacking. So those who dislike the concept of "turtling" will no doubt be happy that the scale has been tilted in favour of civs that fight aggressively.