I'm curious how long you've had to suffer the silent treatment/disappearing and reappearing.
There is no way to tell. Past behavior is probably the best predictor.
The better question is what can YOU do to have a fulfilling life while your pwBPD is doing something else.
One of the reasons that they do this... .is they get some kind of reaction/impact from it.
If you move on with life... .it is likely (but not guaranteed) that this behavior will get better.
FF