When copy/pasting a FC in the same GDB:
The new FC will have a different name, since duplicate names aren't allowed.
However, the alias from the original FC will be brought over as the alias for the new FC. We often don't think to change the alias, so it means both FCs will have the same alias.
It's very confusing when two different FCs have the same alias (seemingly the same name) when dealing with them in Contents, Fields, Attribute Rules.
Could Esri change that behavior so that the new FC doesn't inherit the alias from the old FC? And just make the alias be the same as the FC name -- until the user changes it? I think that would be the preferable option.