Okay, it might not be a bug we can call it feature :)
When an object has a history and you would like to rename the current UV Set it will produce error.
Case one:
There will be a new UV Set with the name you just gave.
Case two:
The current UV Layout will disappear
Case three:
Maya crash
Case four:
I had a situation when the unwanted new UV Set had a new UV layout as well.
And you should know you can't undo these operations. You definitely can't undo when maya crashes.
Fortunately if you delete the history before renaming it will work.