I guess "Degen" in this context means [1] a person "engaged in high-risk, high-reward strategies without much regard for potential losses. These individuals were seen as reckless, often gambling with their investments in the hopes of striking it rich."
Why do I say that degen communism is authoritarian? "The only correct political ideology". That is, "agree with me or you're wrong". That's authoritarian, in mindset even if not in ideology. And if the proponents start with an authoritarian mindset, the ideology will become so soon enough, even if it doesn't start that way.
[1] https://woolypooly.com/en/blog/degen