The Japanese naming scheme reflects the position of the later GX cameras more accurately:
GX7 = GX7
GX8 = GX8
GX85 = GX7 Mk II
GX9 = GX7 Mk III
So the GX9 is really a successor to the GX7 line, which makes a lot of sense.
I found these to be excellent and surprisingly hefty cameras. Must just be me but I do somehow prefer the fixed, less fiddly viewfinder of the GX85...
I imagine to ride the current trend of putting top AF & other spec into even the most entry level offerings, the next GX will have Panasonic's newer 153 point AF system in order to be competitive. They'll become some hard-hitting little powerhouses.