Overall, that paper is mostly the same as this one, comparing "tankie" subreddits to demsoc and anarchists ones and drawing the same conclusions about "muh extremism".

I then noticed this claim:

[The idea of tankies dismissing the Uyghur genocide] is strengthened by reports of r/GenZedong (a tankie subreddit) showing aggression towards Uyghurs online.

Seemed suspicious. They cite a Time article about harrassment on Reddit that mentions in passing:

In subreddits about China like r/sino and r/genzedong, users attack Uyghurs and promote violence against them.

The sources for these two claims are two posts on r/chinareddits. This is like Ethan Klein sourcing all his Hasan footage from r/destiny. The post for the latter claim has been deleted by the creator, but for "users [verbally] attacking Uyghurs" the evidence is this:

Users piling on a "Uyghur activist" who works in motherfuckin' Guantanamo Bay.

And just this one person, so talking about harrassmnt of "Uyghurs" plural is unsubstantiated extrapolation.