There are two bumpers listed under RealOEM for the US market - One with PDC/with headlight washers and one without PDC/with headlight washers (no option for without headlight washers). Photo is a brand new in the box US bumper with PDC. Although it looks like a knockout tab remnant on the headlight washer hole I did not knock anything out.
If you look at the European M bumpers there are 4 options: 1) No PDC/No Headlight washers, 2) with PDC. 3) with headlight washers 4) with PDC/with headlight washers. So I think clever folks order the European bumper to get a no headlight washer version.
Based on what you have said, I would make a guess that the previous owner filled the existing holes.
Between the various bumper options, 2 different washer fluid system (one with "intensive") and the double hoses required for intensive, 2 washer bottles and 3 pumps required the BMW engineer kinda went nuts. That should have put that person in charge of cup holders - we would have had more options than a modern minivan.