I think announcement board is somehow different, even the recent created thread can be in page 2. I do not understand what pump located beside but farthest away from reply icon means, maybe it can take the thread to the first page.
In Announcements (Altcoins), threads are sorted by their bump score.
If two or more threads have equal bump score, then they are sorted by their last post time.
Threads with zero bump score usually start in the 2nd page. So, if someone with zero bump power makes a reply in a thread with zero bump score now, the thread would move to page 2.