Haven't read the paper yet, but based on my personal experience in the barbaric wastelands of reddit and twitter I disagree. Imo the reason removing dislikes/downvotes works on hexbear is that you have strict rules and active/responsive mods that enforce them. I bet it takes a much higher than average (among lemmy communities) amount of work to build and maintain.
In places where that isn't the case, downvotes are a decent stopgap for lazy mods.