Is it possible that the nose for the BGP1 was inspired by the F2001? 2001 was, if you recall the last year before the FIA raised the front wing twice in (2002?) and again (2004?). With the new reg allowing a lower wing, getting the air around the front wheels is different. My hack aero sense tells me that the droopy and slightly wide nose allows for clean flow over the center of the car while creating a low pressure zone immediately behind the droop which helps absorb some of the high pressure wake from the inside of the front wheels. This looks to be the thinking of the Williams as well. But I ask if Ross Brawn remembered something aero notable from his days working with the F2001 that moved him to mimic it on his maiden car. Sure the center section of the wing is FIA spec'd neutral but the downforce generating sections are still much lower like in 2001.
On the other hand, Red Bull and Toyota both have fast cars with much higher noses.