I personally feel there should be at least a female option on the insurgents side. For variety and to give the option to those that want it at the least. Is it a pressing issue that needs to be sorted out ASAP? I don't think so. But considering how much of a focus the long-term player progression has on entirley cosmetic unlockables- which aside from perhaps...camo...have little to no gameplay advantage....It makes sense to provide as many possible options to incentivize as many potential players out there. The arguments against it from a "realism" standpoint, are shakey at best given the games focus as a round-based, squad-centric game first, and a "realistic depiction" of modern combat second. I personally haven't seen or heard any criticism or 'drama' about the games current female playermodels, beyond this forum and if the past entries in the series are anything to go by - modders and sever admins will have plenty of options to tailor the game for their specific vision of what it should be.
To that end I think the base game having:
3-5 security female models and voices
1-2 insurgent female models and voices
and 8-10 male options on both sides.
Would be a solid foundation for others to build off of or narrow down as they see fit - with mods and server plugins down the line. And would be the most bipartisan approach to an otherwise highly debatable issue.