- Should Python documentation refer to the specific version of Unicode
that it supports?
You mean, mention it somewhere? Sure (although it would be nice if the documentation generator would automatically extract it from the source, just as it extracts the Python version number).
Of course, such mentioning should explain that this is specific to CPython, and not an aspect of Python-the-language.
Current documentation refers to old versions. Should version be updated or removed to imply the latest?
What specific reference are you referring to?
- How UCD updates should be handled during the language moratorium?
It's clearly not affected.
During PEP 3003 discussion, it was suggested to handle it on a case by case basis, but I don't see discussion of the upgrade to 6.0.0 in PEP 3003.
It's covered by "As the standard library is not directly tied to the language definition it is not covered by this moratorium."
Should this upgrade be backported to 2.7?
No, it's a new feature.
- How specific should library reference manual be in defining methods
affected by UCD such as str.upper()?
It should specify what this actually does in Unicode terminology (probably in addition to a layman's rephrase of that)
- What is an acceptable level of variation between Python
implementations? For example, if '\UXXXXXXXX'.isalpha() returns true in one implementation, can it return false in another?
Implementations are free to use any version of the UCD.