I think this is entirely arguable. Look at how lego lines dictate what their gender ratios are in respect to their marketing; Nexo knights has a 4:1 M/F ratio whereas Elves boasts an inversion. The former and latter are both marketed as gender specific lines. You can't tell me there isn't a correlation there.
To be clear, I'm not claiming that it's the only reason, but think it's foolish to dismiss it as not being a factor.
Of course not, and I'll concede this point; it was poorly conceived and expressed. Most of my reasoning was backed by anecdote and I suppose more legitimate research could be done on the topic.
HOWEVER, a point I neglected to make is that it's not just the child who purchases the media and toys that introduce them to the line. Perhaps little Jane likes the look of the Bionicle sets she sees at the toy store, but buying this building set with a bunch of robot guys may not pass through grandma's mind when she's making her Christmas orders. There are more factors, which is why historically Lego has marketed their lines with target groups, but in my opinion this looks awfully like self-limitation. Many children might actually thoroughly enjoy toys intended for the other gender if they were actually given a chance to play with them and supported by their elders and peers in doing so. I think that perhaps bionicle might be one such case if handled correctly. And having more female characters in the main cast might help keep consumers from simply dismissing the line as an option because it's a "boys toy", perhaps only just for the sake of a double take.
I understand that this is arguably moot because most consumers don't associate action robots with girls' toys to start with, but once again marketing could help that mindset change. And isn't Bionicle having an awfully narrow audience the main reason we assume it failed, why we're moving from constraction to system? Suppose there's any way to broaden that, even one this minor, isn't that our prerogative to take?
But they aren't the Toa Mata. They're redeveloped characters based on certain traits of the Toa Mata.
And reboot characters are more than just the old characters "In name only"? They aren't part of the same continuity, they don't live in the same universe... But they are based on the same ideas. Gender doesn't necessarily play a significant role in that.
Lewa could still be that adventurous Toa of air that gets in over their head in trouble and happen to be female in this iteration.
Sorry if I didn't touch on something, you two threw a lot at me there. If I missed anything, be certain to let me know.