I also cc python-dev to see if anybody here is strongly in favor or against this inclusion.

Put me down for a strong -1.   The proposal would occasionally save a few keystokes but comes at the expense of giving Python a more Perlish look and a more arcane feel.   

One of the things I like about Python is that I can walk non-programmers through the code and explain what it does.  The examples in PEP 505 look like a step in the wrong direction.  They don't "look like Python" and make me feel like I have to decrypt the code to figure-out what it does.

   timeout ?? local_timeout ?? global_timeout
   'foo' in (None ?? ['foo', 'bar'])
   requested_quantity ?? default_quantity * price
   name?.strip()[4:].upper()
   user?.first_name.upper()


Raymond