In the United States, the national conference of Catholic bishops rejects the concept of gender transition, leaving many transgender Catholics feeling excluded.
Does the Venn diagram have a big overlap? If I were trans (very important note for my question, which is likely ignorant), why would I now want baptized by a group that has shunned and hated me until now?
You are not forced to. If one is a believer, they are free to practice it. This is all about choice, like many modern and going to be modern things.
It would have not been better if they kept shunning it. They know the practice of the religion needs to be adapted (as in fact, its a belief), as it always did in modern history. An example of this is also the transmission of the services in television, despite it not being considered an "holy" way of transmission.