Well Discord, allows "Cub", which is basically worse then loli in my opinion. Discord selectively enforces their rules on things they don't like but allow niche things like cub which is basically baby animal Pron, even though its fictional, they don't follow their own sets of rules. https://www.reddit.com/r/discordapp/comments/ak3g4j/we_do_not_consider_cub_to_be...
Also the fact, your server never actually violated any of Discords policies. Since the server was up for 2 years at least, its obvious someone who was trigger happy, banned it. How I see, it is a wrongful termination of the server. And since they're vague in their reasoning for banning it, it is without a doubt hypocritical for Discord to ban the server, when they themselves can't even name any actual policy the server broke, and since their were no actual pictures "depicting minors' since drawings are not real, and their actually needs to be a child to "depict" other then that since their is no actual child involved, they have no argument, and they won't be able to defend that position they are keeping. Because they are making claims that simply do not exist.