The definition of transgender is anyone who identifies with a gender other than the one they were assigned at birth. It is therefore an umbrella term that includes nonbinary genders.
I’m not trying to be antagonistic but wikipedia disagrees with you as well. This opening paragraph on the subject has citations from these publications:
How do you understand this take then?
that person is wrong. transgender isn’t an umbrella term.
I’m not trying to be antagonistic but wikipedia disagrees with you as well. This opening paragraph on the subject has citations from these publications:
https://books.google.com/books?id=NAjmBQAAQBAJ&pg=PA740#v=onepage&q=&f=false
https://www.apa.org/monitor/2018/09/ce-corner-glossary