To anyone asking about the automatic kicks from the Discord server, the invites the owner was issuing are a specific kind of invite that Discord offers, called a temporary membership invite. These invites automatically kick the recipients from the server after a short while or after they go offline unless they are given a role, which the server is explicitly set up not to hand out to guests currently. You're not banned after these kicks, but it does mean that you have to rejoin the server (which I suppose in and of itself can be frustrating when you want to stay in the know about something with very few means of communication). To remedy this, I reached out regarding the issue and helped the staff team make the invite link that just got created and posted about 20 minutes prior to this post. This link will not expire and is not a temporary membership invite.
The downside of this whole concept is that the server currently seems half-baked, currently missing important features like a means to top-up using the advertised vouchers and being the rare server I can't connect to without a VPN. As important as getting a playerbase can be for a private server like this, if core functionality is missing, I can't in good faith say advertising the server is a beneficial decision. Maybe, given time, the server could bloom into a nice community, but we are currently far from that. I like what is being offered, so I'm going to stick this one out, but currently this is more of a waiting pain to see if the dev team can handle the growing pains.