“Republicans repeat propaganda and democrats don’t” isn’t even the conclusion of this paper, which you’d know if you had actually looked at it. In fact, we already knew that republicans spread more disinfo than democrats, it’s been demonstrated in multiple studies that are cited in this paper.

This particular study’s interest is about what triggers it : “Our research enhances our understanding of when and why conservatives tend to spread more misinformation than liberals. We find that an ideological asymmetry emerges when politically polarized situations trigger conservatives’ desire for ingroup dominance. Acting on that salient desire, conservatives spread ingroup-skewed political misinformation, which is of uncertain accuracy, but not definitively false. In less polarized situations, conservatives’ desire to achieve ingroup dominance is tempered, along with their misinformation conveyance.”