(emphasis added)
You are exactly correct, and that is precisely my point.
Dictionaries have multiple entries for the same word. We have two definitions being tossed about in this thread. I'll put the newer one first.
Woman

1. A person who performs the feminine gender role as defined by society.
2. An adult human female.
The nature of transwomen does not change if I use definition 1 or definition 2. Words do not create reality, If I say, "Transwomen are not women", that means I am using definition number 2. If I say, "Transmen are not women", that means I am using definition number 1.
By definition, transwomen either are or are not women, depending on which definition is in use.
(Note: My definition number 1 above is my best attempt to summarize the various contributions seen during discussions of definition. If you wish to object to it, feel free, but if I may, I would like to make a request. If you wish to say that the above definition is not actually a definition that is in use on this thread, please offer a substitute definition, and in doing so, please make it in the form similar to what might be found in a dictionary).
We have two definitions of "woman" being used in this thread