Exactly. I don’t know if I’m missing something, but a fork is probably possible just by replacing the trademarked „Wordpress“ inside all translations, and a few minor code changes. Variable names/etc inside the code with „wp“ or „Wordpress“ probably don’t violate the trademark.

I would estimate a proper fork could be done by 3 developers within two weeks, but whoever is doing it, should get some backing by a company (probably also easy) and some legal consulting.