It is not a horseshoe, as it is not a continuum. Far-right is pre-modern and far-left is post-modern, and both have a distinctly different view in opposition to the modern enlightenment project. However, the current dominant ideologies on the fringes seem to share some important core tenets and a tendency towards tyranny.

Btw, the article you link seem to argue that there is a historic parallel to this argument. However, post-modernist is a much newer concept and ideology than the historic events listed in it.