[2019] I finally understand what the meaning of "you do not need restart your client"

@mndfreeze has it. When we release a major version, you'll always need to restart your clients (and sometimes Steam) to download the update, otherwise, you won't be able to connect to any updated servers. This is in the case of going from v15 -> v16, etc.

Sometimes we'll release minor client updates, they're usually just to make sure the client is aware of changes on the server but aren't necessary to play/enjoy the game, though we always recommend downloading them if we do push them out. For instance, with the FOY update, when we added the additional fountain, it required a client-side update so without it, you would have only seen the one -- which would suck cause you may have ended up travelling to the island where you couldn't see it.

Typically our updates are server-side so they don't require clients to download patches, just redeploying and updating the servers.