Dealers do this all the time to generate extra cash.
During part of the recall (which is free), they often piggy-back something else.
I have had this with Volvo, Honda, BMW dealers over 25 years.

Best is to install the ebay airbag emulator for $15. I did this on my E39.
This seat occupancy sensor is a piece of garbage engineering.

__________________
1998 E39 528i 5sp MT
2006 E53 X5 3.0 6sp MT