That would be great wouldn't it?
I can imagine if Frontier adjusted the axis points on all the fences now, it would ruin a lot carefully manicured parks out there...
It is possible. Frontier can phase out the old fences by hiding them from the scenery browser, and add the new/updated fences with the different axis point. The old ones remain compatible and can even be used still if someone finds a blueprint with it in there since they still exist in the game's object database.
or they develop a fencing tool that does that axis placement while you're using the tool.
There's lots of ways it can be done, but it's probably not a priority issue to them.