Hello,
I noticed that a thread I recently posted in no longer has the dot to indicate as much. It's http://paizo.com/threads/rzs2sy87?Specifics-of-a-Lichs-life#23
I have noticed in the past that sometimes threads stop showing the "(25 new)" markers, which might be related. I assume that one's actually Paizo recognizing that it's not worth your time keeping track of which posts I have read after a certain point. This one seems less likely to be deliberate, though.
Not a big deal, so feel free to leave it alone. Gotta report my bugs, though. :-)
Thanks,
Berinor