If this were to happen, players could gradually change their group to an entire different name, lets say someone decides to change 1-2 letters in their group name. They could keep changing 1-2 letters over time so it makes it to where their group name is something entirely different.
I don’t see an issue with allowing changing of capitalisation for free, but I still think Roblox should charge to actually change your username.
However, if this “Display Names” feature is what I think it is, we could be looking at using a system like Discord where you can change your username, and it’s a combination of username+discriminator that identifies you.
There would have to be some way to keep track of previous changes. Obviously there are more aspects involved and it isn’t very simple to implement this system right away.