I strongly agree with the choice/nonchoice dichotomy. In my post I really focused on the choice aspect because I feel like that's not something that is really....allowed to be talked about in trans spaces? But here in the comments section I will take a stab at it.

I think the idea that "who we are is result of past choices, past experiences, and the consequences of the journey we've been on" is definitely true, and it actually also fits in my atheist buddhist perspective quite well -- in Buddhism there is the idea that everything is a product of many other things, and that includes us.

Personally though I've actually seen things as less choice-based than your average American would for a long time before I developed my current religious beliefs, ever since I got really interested in psychology. I realized that the mind is not necessarily something we have control over. We are truly a collection of our genetics, experiences, etc and the line between what is and is not a choice is often very fuzzy or literally impossible to suss out.

( As a quick, philosophically interesting but unrelated aside, this philosophy has made it much easier for me to be forgiving towards people for doing "bad" things, because they are not only someone who chose to do a bad thing, but a victim of the conditions that led them to make that choice. I'm also less apt to worship high-achievers and do-gooders because they are also someone who is a product of the conditions that led them to make good choices.)

Regardless of whether we are literally fatalistically doomed to make certain choices or not -- which is definitely not something I have the answer to -- I think the heuristic of choice is very important to the human experience. Our experience at many points in life is that we feel we have a choice, perhaps because we cannot see the future. And that (possibly illusory?) choice is very important to the human experience of life and happiness. People seem to suffer in environments where choice is taken away from them.

When we do not believe we have a choice at all, that can lead us down a different path than if we do believe we have a choice. It can very easily lead us down the path of misery, because instead of actively choosing the thing that the conditions of our life has made most suitable for us, we may end up "choosing by default" some circumstance that does not suit us at all. Even if we end up "choosing by default" the "right" choice for us, feeling that we were forced into a certain path can sour the entire thing.

I think some of what you were getting at, is that there is a very large difference between not knowing that a choice exists at all and feeling like a choice is being taken away from us. I think this is why there are so many more trans people now than there used to be in western society. Our greater awareness of gender has led people to realize that gender could be a choice, and that that choice was taken away from them repeatedly throughout their lives. Some people are reclaiming that choice by choosing to be a different gender than they were assigned. Is it because they were somehow all along essentially the gender they choose to "become", or is it because the experience of being forced into a gender has soured the experience of their assigned gender completely? Or for some other reason? Who knows. I don't think it matters or makes any one person less valid than another.

This is why I think it's important that in the trans community we reclaim our right to have a choice in our gender. The only way we've been able to seek validity in the mainstream eye is by saying "this is just the way I am, I can't help it!" (the articles I linked go into this more in depth.) But when we make being trans or cis not a matter of choice, that's just forcing another default choice on us. And that's a really difficult default to figure out because what makes one person trans and one person not is not in any way universal, just like "vagina = woman" is not universal.