The reason I'm asking is because I started the encryption process and then a window appeared that said: "Bitcoin Core will now shut down in order to complete the encryption process. For security reasons, previous backups of this wallet will become useless as soon as you start using the encrypted wallet."

What does this mean? Will it move my funds automatically, or will it just flush the address pool or what exactly will it do?

I don't want it to move any of the balance unless I actually do a transfer!