Beretta OEM mags have both notches. At least all the ones I have (haven't bought any in 3 years or so) do.
My understanding of it is, Beretta just produced them with both notches so they could keep production simple while being able to supply all their government contracts. The 92s are only recently getting replaced in the several European police agencies that used them, so it made sense for Beretta to keep supporting it.
I doubt they'll update the production now that the 92s is effectively being sunset. Why bother? It would cost money to update the production lines, for no cost benefit.