CoG limit applies to all operators, however not all operators find the limit to be limiting, if you know what I mean. I know of one operator that checked their historical load data and found they’d never loaded aft of the new limit, not that they’ve had the neo for long.
The 320 issue is not the same as the 321. The 321 will be fixed with ELAC L103. The 320 problem was discovered by computer simulation and requires a very specific set of circumstances. The 321 problem was discovered in flight testing.