God please NO!
I would KILL not to make that happen. So many devs abuse those in every language that has that. Even lambas get sometimes abused in Python (and I have a few examples in our codebase unfortunately). Expanding lambdas' scope is the LAST thing I want in Python, this would just lead to worst codebases, with nearly 0 benefit.
If you want to do something that needs 2 expressions, just create a goddamn function and name it for god's sake.
Sorry but I had to say it, I think the lambda limitations is one of my favorite feature in Python.
It could and could also not be useful to give names to all the subexpressions in the following
w = a(b(c(x,y),z))
You could impose a limitation on how many function can be in a single expression, forcing you to give names. That's analogous to your favorite feature, no?
There's so many cases (arguably including the problem this PEP was designed to solve!) where having a real inline closure is just far more readable than having to arbitrarily break every single thing that happens to need 2+ expressions out into named blocks out of sequence.
Other things in Python are either simply a result of the language's age and history, or have real technical pros and cons, but that one irks me because it's an artificial limitation chosen for no reason except aesthetics.