James Cameron, like many filmmakers, has found various crewmembers, especially at the higher levels, that he prefers to work with, and as such, when he went to work on his newest project, he called them in., The thing is, these people are likely to have been working in Hollywood for decades, just like Cameron himself, and so they are more likely to be men because that was the status quo when Cameron began making a name for himself.
For what it’s worth, it seems the reason for this isn’t so much based in any sort of intentional avoidance today as it is a relic of an earlier era.