Glenn Linderman wrote:

I wonder how many raw strings actually use the \"  escape productively? Maybe that should be deprecated too! ?  I can't think of a good and necessary use for it, can anyone?

Quite rare, I expect, but it's bound to break someone's code.
It might be better to introduce a new string prefix, e.g.
'v' for 'verbatim':

   v"C:\Users\Fred\"