Try asking ChatGPT to list academics who use TeXmacs. It seems to be making stuff up, maybe because it is confusing TeXmacs with TeX?
ChatGPT hallucinates about who uses TeXmacs
Hi, it seems that ChatGPT knows TeXmacs and don’t make confusion with TeX.
Here is what ChatGPT says about TeXmacs 
"TeXmacs is a free and structured scientific text editor that allows the input and display of complex mathematical documents. It was developed by Joris van der Hoeven in 1998 and is written in C++ and Scheme. TeXmacs offers a composition environment similar to LaTeX, but with a more user-friendly graphical interface.
TeXmacs works by converting documents into an internal XML format, which makes it easy to manipulate data and convert it into other formats. It supports document editing in several programming languages and allows users to integrate interactive elements, such as graphics and simulations, into their documents.
The software also offers compatibility with other document composition systems, such as LaTeX and Mathematica, allowing users to work with files created in these formats. In addition, TeXmacs can be used to create presentations, scientific papers, books, and other types of documents requiring complex mathematical expressions and formulas.
Overall, TeXmacs is a versatile and powerful tool for creating and managing scientific documents, offering a user-friendly interface and a wide range of features to meet the needs of researchers and educators. "
I think sometimes it is confused and sometimes it is not.