"We can't just compare pre to post, we have to compare pre and post to the general population if we want, as too many say these days, that transition is a cure."
You are free to do a study comparing post to cis. This particular study is not about that - it is about pre to post. "Cure" is not quite the word. I am post and I still have some gender dysphoria, but I went from desperately unhappy for many years, to being happier than I knew it was possible for a person to be. Sure, I get twinges of dysphoria from time to time but, to make an analogy, imagine if you used to suffer intense profound headaches every day for many years starting in your early childhood. They were so intense, you couldn't get on with a normal life - you just hid away, desperate for the pain to go away, crying yourself to sleep and wondering what the point of being alive was, then you tried a new therapy and your life is transformed. Now you still have occasional headaches, so you could say that you are not exactly "cured", but the headaches are mild - last a hour or so and don't impact on your day to day life or your general happiness.
"The vast majority of dysphoric people don't transition"
Do you have a citation for that? I would be interested to see it.
"As self medicating on hormones is having resurgence today and dysphoric people get less and less face time with professionals, it's likely the current cohort will differ from Dhejne's better cohort."
But we have the internet now, with lots of forums where people can learn what safe doses are and where to acquire genuine hormones. We will see where this is all heading in due course, though the Cornell study does go up to 2017.
"Also 56-73 studies isn't really 'huge'. Many meta-studies look at hundreds. This is a small-medium one."
It's by far the biggest done on this particular group. If you have a larger one, perhaps showing the opposite result, you are free to post it. If not, then I am sure you will agree that we can at least say that according to the best studies we have, transition has a positive effect on people suffering from gender dysphoria and we can therefore discount claims to the contrary unless those making the claims present evidence that supersedes the Cornell study.