Sov doesn’t need more space, the space we already have isn’t being fully utilized. In fact in terms of player count and activity High Sec is the area of the game closest to full utilization and even that’s a pretty far cry from being “filled”.
In short the one bit of reasoning you had for this change doesn’t hold up to even casual scrutiny. This would be a pretty massive and drastic change and there’s no good reason for CCP to do something like this.