I'm not really sure it's a complete disappearance, actually. Celebrities often change their relationship with social media - she might have just put her phone down for a while, it's become pretty common. Lots of stars realize social media has gotten too much, and they take breaks without announcing it to the world. It could be for her mental health, to protect her privacy, or just because she was tired of the endless cycle of posting.
Anyway, without access to her actual reasons, we can only speculate. She might have a project going on where she wants to keep the focus elsewhere, or she's dealing with personal stuff away from the spotlight. Sometimes artists also decide to be selective - rather than disappearing completely, some just post less and more deliberately, like to control their image. If you liked following her, honestly the best thing is to wait for her to come back at her own pace, or check celebrity news to see if she's said anything about it.