Pitch and lateral control switching (ground - flight) is not related to weight on wheels. The trigger is when the pitch attitude is greater than 8 degrees. At this attitude, the timing starts for a gradual transition from ground to flight mode. That's how I read my (A320) FCOM anyway!
I don't think the side stick indicator logic on the fleet I fly has been updated on all variants and cannot find the memo we were sent a while back about this. The newer aircraft have a new DMC standard (green VDEV scale on PFD in DES) and I think the new logic could co-incide with this standard.