She never left. I mean during her "decline" she managed to gross the same touring receipts that most girls gross, got a grammy, critical acclaim, starring as the lead in a tv series etc..
ARTPOP was a very messy time for her in the public's eyes so that's what I meant by "left". She undeniably hit a huge rough patch of negativity & disappointment in her career 2/3 years ago.
No. Her image is repaired and so is her relationship with the GP, but the music has to be good. If the music is good, it will do well. That's when we'll know if she's back