A new idol from Grandis has arrived!
This class does not use MP but Soul Charge instead. Recharge your skills with Soul to be able to use Soul Skills.
You can also use the Dress Up system to dress up your character to be the perfect Barbie, uh I mean Angelic Buster.
"This is how it works: you're young until you're not, you love until you don't, you try until you can't,
you laugh until you cry, you cry until you laugh, and everyone must breathe until their dying breath."
^ Chances are that was probably hearsay and not a reliable source. Unless Nexon says it themselves, you can't trust what other people say that Nexon supposedly said. (And sometimes you can't trust what Nexon says either but that's another matter)
Besides, the game thrives on new content, and new content includes the occasional new class. So long as Maple continues to grow, I have no doubts that there will be more classes in the future.
I think what you read was probably that Luminous was the last HERO that was going to be released, which is true.