There are 3 major flashpoint chains. There's Essless/BT, Foundry/Maelstrom, and False emperor. These are the full length, story mode flashpoints. Some people don't care too much for these kinds of flashpoints. So they made the ones that are lighter on the story like hammer station, athiss, etc etc.
Yea I think people don't realize that the 3 production quality flashpoints have been in the game/beta for a loooong time. All these new ones were thrown in within the last 2 months.