Adding to what Ebornheart said, it's one of the rules on Discord.
You've got your hard bans (scat, vore, underage, murder, etc) but the bolded line hints at being broader than that. Basically, if Inno stated at some point she doesn't want to add or support it then it's safe to assume you're not allowed to discuss it either. That is what the rule implies. This would also explain the behavior discussed above, and why the whole Discord avoids certain topics altogether...
Granted, you probably won't be banned for talking about generic fantasy races but it is a moot point. Developer already state she's not adding or inclined to support them and the community tries to enforce her vision and mindset.
I think it's silly. For example, there's nothing wrong or illegal about liking generic fantasy races, but with this rule you're basically forced to scour the internet for a modded version that has said content. And just because you wanted to play with elves, no one on Discord will want to help you because "eww, modded version from shady website" and all this because Inno forbade said content out of personal preference. Not even a big reason, just "I don't like 'em".
Websites like F95 and Chan become essential if you want something unofficial done to LT...