As a hardcore, and lifelong Bond fan, I might get flak for saying this, but:
I'm totally fine with this. If they're not changing James Bond the character, and simply giving the 00 to another person, i'm totally fine with it. They're leaving Bond alone and the universe continues? I'm good with it.
Except James Bond is 007. After 50+ years they are literally one in the same. Not to mention I believe the franchise has used that actual line as advertising before. Have her be a different 00 instead of ruining the movie by pissing off the fans. As far as I remember 006 in Goldeneye is the only other 00 we have actually met on screen, so its not like they can't fill things in with other 00s. Have her be 009 I think it was that Q said the car was originally for in Spectre, unless he said 009 was a guy, I don't remember. There is no reason to give her the 007 number except as a way to tell the established fanbase to piss off.
So would the 'fanbase' be pissed off if a British white guy replaced Bond's 007 codename? ---