Yes, libreoffice doesn’t really work for live collaboration. But office online is a good solution for that collaboration, and it works in any browser (including Firefox on Linux). Therefore, the author’s conclusion (you need windows to collaborate on word docs) is still wrong.
I personally also believe that WYSIWYG editors are highly overrated: markdown is significantly better for note-taking and similar small documents, and reports would often be better off with LaTeX or something similar. But I understand why the “4 commands is too much hassle to install VirtualBox” crowd might prefer word.