Terry J. Reedy added the comment:
I think that this proposal is either premature or not needed. (But did you
have anything specific in mind.) As you indicated, there are two separate
subissues here.
1. NotImplemented: Issue 35712 added "It should not be evaluated in a boolean
context" to
New submission from Steven D'Aprano :
Truth testing states that "Any object can be tested for truth value" but from
3.9 onwards, doing so with NotImplemented is deprecated and will be made a
TypeError.
https://docs.python.org/3/library/stdtypes.html#truth-value-testing
It is also not true
