The later cars have a special sensor on the battery and a set of special algorithms in the Central Electronic Module that is supposed to "intelligently" monitor battery age, temperature, current draw, and voltage and then be able to shut down non-critical systems before the battery is discharged too far.
The issue is not that more electronics are draining the battery. The issue is that, when the battery is replaced few shops (and fewer owners) know that they need to reset the battery age through VIDA. If the car thinks the battery is old, it will begin shutting down ancillary systems sooner because it believes the battery is old and cannot tolerate the same amount of discharge that a newer battery could. Basically, the car's "intelligent" battery controls are more protective of what it believes to be older batteries so people well get the "low voltage" warning earlier if the system thinks the battery is old than they will if the system knows that the battery is new.