It's also pluralised.
"The will will introduce female Predators".
Could it be there's more to it and we get another ship scene like in P2? Might explain the extensive re-shoots.
Or is it more likely that it'll just be Treager/Keyes alluding to the fact that they've had/seen two genders of the species?
As there'd have to be a visual cue for the audience and, sadly, I think that'd be breasts. It's just the more obvious choice for cinema.