The issue with this change was, that someone who was previously named Mike for instance with a discriminator, has to now choose something else for instance: "Mike372". Discord claims this is a better and a less confusing system, when it really just boils down to the same thing. Making matter worse they claimed all Mike usernames are taken, so #0001 to #9999 which also later turned out to be false, it was just their site choosing a random discriminator, which when it was already taken told you: "This username is already taken.", when in reality there were still available discriminators.