Why would that necessarily be true? After a celebrity dies, a short amount of text is expected to be added about the death, but beyond that, why would you expect the length to increase?
Heck, even the simple increase of eyes on article seems like it'd increase the edits. Then there is the potential for reporting on something to cause people to add / amend the relevant articles.
Still, since it plausibly could be a factor it is something that should be ruled out.