In my view as a long-time moderator, the purpose of moderation is conflict resolution and ensuring the sitewide rules are followed. As reported today by !vegan@lemmyworld, moderator Rooki's vision appears to be that their personal disagreement with someone else's position takes priority over the rules and is enough to remove comments in a community they don't moderate, remove its moderators for the comments, and effectively resort to hostile takeover by posting their own comment with an opposing view (archived here) and elevating it for visiblity.
The removed comments relate to vegan cat food. As seen in the modlog, Rooki removed a number of pretty balanced comments explaining that while there are problematic ways to feed cats vegan, if done properly, cats can live on vegan cat food. Though it is a controversial position even among vegans, there is scientific research supporting it, like this review from 2023 or the papers co-authored by professor Andrew Knight. These short videos could also work as a TL;DR of his knowledge on the matter. As noted on Wikipedia, some of the biggest animal advocacy organizations support the notion of vegan cat food, while others do not. Vegan pet food brands, including Ami, Evolution Diet, and Benevo have existed for years and are available throughout the world, clearly not prohibited by law in countries with laws against animal abuse.
To summarize, even if you don't agree with the position of vegan cat food being feasible, at the very least you have to acknowledge that the matter is not clear-cut. Moreover, there is no rule of lemmy.world that prohibits those types of conversations unless making a huge stretch to claim that it falls under violent content "promoting animal abuse" in the context of "excessive gore" and "dismemberment".
For the sake of the argument, even if we assume that the truth is fully on Rooki's side and discussions of vegan cat food is "being a troll and promoting killing pets", the sitewide rules would have to be updated to reflect this view, and create a dangerous precedent, enabling banning for making positive comments about junk food (killing yourself), being parents who smoke (killing your kids), being religious "because it's not scientific" and so on. Even reddit wouldn't go that far, and there are plenty of conversations on vegan cat food on reddit.
Given Rooki's behavior and that it has already resulted in forcing the vegan community out of lemmy.world and with more likely to follow, I believe the only right course of action is to remove them as a moderator to help restore the community's trust in the platform and reduce the likelihood of similar events in the future.
From a strictly scientific perspective, it is inappropriate to use where something fits into a recognized classification system as some indication of broader scientific fact. That's an oversimplification that takes what is a simple teaching tool for lower-level science education that, by necessity, smooths over the details and nuance of our actual physical world, and tries to more broadly apply it to the actual practice of the science by specialists who actually work with that detail.
You cannot actually say that because something is classified as an obligate carnivore, it must consume meat to remain healthy. The classification system is too flawed for that, and exists merely to teach some basic principles in biology to new students. Our classification systems are not based in immutable fact and intended to be the end-all-be-all for drawing conclusions. Instead they are working tools with imperfections, designed for a specific teaching and communication purpose.
The fact of the matter is that a living organism requires certain chemical inputs, and if those inputs are provided, it can potentially remain healthy. If we simplified this down to some carnivorous bacterium, I think you could see a little more easily how we can very likely engineer around any classification of obligate carnivorousness if we so desired. It's classification would not necessarily be accurate as described anymore, though that would not mean we should necessarily discard the system when it still serves a useful purpose for analyzing animals living within their natural habitats.