I think if you care that much about not wanting storylines then Melanie will never please you. It seems like it’s what keeps her passionate about making music. I think the reincarnation story is a good middle ground to please both fans who still love Cry Baby and the ones who want to move on. It’s just her consciousness in another body and I doubt it will really make a big difference that it’s her “soul” but probably just something to make the huge change hit less harder for the long time fans.
I’m personally fine with the storylines as long as she doesn’t restrict herself to such strict themes like she did with K-12. The Cry Baby story was fine because there was so much to work with.