I don't believe it does. At least it never used to, I've come back to a topic later, without it saying new, and noticed the last post was edited.
Hmm. The reason I was asking is because Obed had the last post in a topic but it kept coming up as new, even when I clicked the topic prior to see it was the same post. I did notice some revisions each time though so I just put two and two together.