I wouldn't go that far. They just became more popular to a broader audience. As you said in a later post, their popularity skyrocketed with the popularity of the film. However, I would argue that their POTC figures were their initial step into higher quality and more detailed figures.
Not true at all. HT already had many, many licensed figures that weren't model kits before the TDK line including their first Batman Begins Batman (MMS13) as well as 4 figures from Superman Returns (MMS14, MMS27, MMS49 & MMS50). Not to mention the pretty popular POTC line stated above that had nearly all the main characters produced except Barbossa. The TDK line didn't start until MMS67 with the Original Costume Batman. That's 54 figures before they dove into Nolan Batman films again.
Check the linked Topo thread near the end. I cant' remember, but there may be some pics:
Topo Toys Joker suit - Dark Knight.