I don't think there's really any need to bring the politics of trans inclusivity into the equation, to be honest. There is no way to answer the leading question "What does a trans person sound like?" that is not, itself, reinforcing a stereotype unnecessarily, or needlessly doing a disservice to portions of the community. Let me put it to you this way: how do you know that none of the already presented voice sets are not, in fact, presented by trans or non-binary individuals? Short of looking up exactly who they are and checking, you don't, and you can't. I've known tans people whom I would never have known were trans unless they told me, voices included, and I've known numerous extremely gender normative people with voices on a broad spectrum that could really go either way.
I dislike that we have such a minuscule selection of voice sets to pick from - none of them sound like I feel like any of my characters sound, and it's discomfiting. This is an experience that will be shared by a broad spectrum of people who play the game regardless of any other factors, and more voice sets across the full spectrum of voice sets would be good - as well as the option for a silent protagonist or no voice set at all, because at the end of the day it will never be possible to cater to everyone's individual character and the option to not have a voice overlay, if you cannot find one that is close enough for you to be satisfied with it, is important as well.
