The point being
that I would expect stub article creation to be pretty high
in new Wikipedias, and to tail off as the Wikipedia in question comes to be
seen as more authoritative.
That's a very valid point. That would contribute to an upward trend of
stub ratios with increasing edits, which is exactly what I see for
Wikipedias with less than 20,000 edits, but after that it levels out,
and becomes much less variable. I can't think why.
Perhaps it's the point at which a project becomes more authoritarian
than authoritative. It's where people become concerned that stubs
somehow reflect badly on the project, and they start to delete the stubs
on that basis.
Ec