Also, I don't think any in-universe content can
easily be rewritten as
out-of-universe, you'd need incredibly detailed sources for that, if I
interpret policy correctly. A section describing the character traits of
some alien race would need to be rewritten along the lines of why and
how the authors/designers/directors made the character that way. In most
cases, sources like that don't exist - which shouldn't keep us from
implementing the proposed guideline changes. The basic premise is that
in fact there is a lot of unsuitable material, we just need plausible
syntax to get rid of it while preserving as much useful material as
possible.
The in-universe statement: "The Blogaveen race has blue hair and green
eyes." can be rewritten out-of-universe as: "In Episode 17, a member
of the Blogaveen race is portrayed as having blue hair and green
eyes." That statement is perfectly OOU, but doesn't require anything
but the primary source. Obviously, information about the creation of
the character would be good, but the absence of it doesn't make the
statement IU.