I too own a GW Macaw (Neleno). I think the better question is are Macaws a one person bird and in most cases they are.
I don't think the sex on ones Macaw or sex of their human owners matters. Macaws see us as their flock mates and in extreme times, may see us as their mates.
I believe, a Macaw selects an owner over one simply due to the amount of time,attn, and takes care of their needs.
Cleaning their cage, feeding, bathing, and just playing with them.
The more you understand your macaw and feed into their needs, the stronger the bond you will have with them.
I too know of many cases where one macaw has bonded with one of their owners and one day, things change and the Macaw is now bonded with another owner.
Who really knows why these amazing creatures bond to humans in the first place but sure glad they do.
I hope this answers your question. Best of luck Joe