Renaming a layout from a snapshot on the RHS is OK as long as there is no other snapshot with the same name (duplicate not shown):-
I am able to reproduce the issue and will create a case; however, I'm not positive this isn't just a side effect of some of the 'by design' behavior regarding renaming layouts.
Thanks Tonya
At the very least the behaviour is inconsistent/unexpected.
The case for this issue has been resolved 'by design'.
Thanks Tonya (for relaying the news!).