That's great!
Unfortunately, there isn't a built-in automated migration process available yet. To transition smoothly, you should create the new community and make an announcement in the old one, pinning it for visibility. Additionally, consider cross-posting the last five posts to ensure the new community doesn't start empty.
The old community is already federated here, which means it will remain on Europe Pub and other federated instances for archival purposes. However, it will no longer federate new content. This implies that any new posts in the old community from Europe Pub will only be visible to Europe Pub users and not to users on different instances. To avoid any confusion, it would be best to lock the community before the server goes down.
Initially, I had the same thought. However, given that it was clearly fake and meant to be humorous without causing any harm, I believe it's acceptable.