It means she's moving onto a new stage in her career. Possibly one that intentionally eschews the mainstream and will ultimately be devoid of top 40 success, if you read it literally. But her ARTPOP could mean anything, so only time will tell
It's also just as likely that she never said anything of the sort. Monsters should know by know that some fans like to make **** up and spread it through Twitter like it's truth tea. Remember the "message hidden in the red lipstick on the BTW cover"?
If it means totally ditching dance-pop then I am here for it. She can still incorporate electronic elements, but songs like G.U.Y, Mary Jane Holland, and Sexxx Dreams need to go away forever. She's done it for too many albums already. That sound is dead and people are over it. She needs to tone down her style and sound. Minimalism is in (see: Beyonce, Adele, Lana, Lorde, etc.)