Did the connectors change? I assume this is because you have electric seats?
Even if electric seats, the only codes sent over the wire is the key number when you have memory seats so that the seat adjust to the last settings used on that key in the E46.
So the F8x seats is where I dont know. Do these cars also have memory based on the key you use (memory is not stored in the key but in the car modules).
So the car only communicates key number to the seat module, the seat module takes care of the saved settings for the key.
So if you have memory electric seats now, and you replacing them with memory electric seats, it should mostly be plug and play if the connects are the same.
The only other thing that the passenger seat will have, is the occupancy sensor.
That is from my limited knowledge on the E46 seats, which I never had, only had cars with manual seats.