48V mild hybrid is clearly confirmed now on bmwusa.com (link below). I've also seen some dealers' listings of 2021 MY vehicles described as 48V mild hybrids.
Greater power, greater efficiency.
The 3.0-liter M TwinPower Turbo inline 6-cylinder engine is further enhanced with the new 48V mild hybrid technology, which delivers heightened eBoost power while optimizing efficiency.
Link:
https://www.bmwusa.com/vehicles/3-se...nce-m340i.html