By my read, this is the core of the articles argument:

But if these billionaires’ largesse was designed to retain the conservative judge on the country’s highest court, the donations might fall outside of the definition of tax-free gifts, which according to the Supreme Court must stem from “detached and disinterested generosity.” If the benefits showered on Thomas were designed to elicit court actions or job decisions, they could be considered taxable income, whether or not there is definitive proof of quid pro quo on Thomas’s part.

It’s one thing to want smaller government. It’s another to want to completely shut down core function of the government. This quote shows that he want to do the latter and I think it clearly illustrates why you would call him “extreme” right wing:

The president-elect also announced that public works would be “cut down to zero” and those already in progress would be put out to tender so that “there would be no more state spending”.

Public works includes roads and other such infrastructure work. He isn’t saying shrink. He’s saying zero. Shutting down core public works is pretty damn far out there.