The Caturday tag is something that has existed for a long time and not just on Steem. I've seen it on Instagram and other sites as well. The Caturday Discord existed before CAT. The creator of the CAT token is in that Discord and a bunch of the supporters of the project hang out there, too. It's essentially a Discord for people who love cats.
Well, it sucks that you have a slow connection because we give out CAT for participating in the Discord and there is also a channel for promoting cat related Steem posts.
Here's an invitation link that doesn't expire; you can use it anytime if you wish to join: https://discord.gg/p7deVuc