Some people started stanning for her because she was a great artist who made great music, not for the simple fact that she just made pop music. For some fans that was subjective.
Regardless, she's going to do what she wants to do and if you don't like it, you don't have to listen

She'll gain new fans. And not all of her fans are going to drop her. Some actually have diverse music taste and listen to other things than just pop music and understand that she's the same artist/person with the same sass, behavior and creativity but with a different genre of music. I just don't see why it matters. As long as she's making great music, it doesn't matter what genre it is.
She never said she's ditching pop though, so that audience has nothing to worry about.