There’s no way Ben would go back to wearing a mask. The way he destroyed it in The Last Jedi perfectly shows how he is ditching the Darth Vader impersonator he’s been acting like and becoming his own force.
That is one interpretation. If Rey had joined him, I doubt he would’ve gone back to the mask. But after she rejected him, he is more alone than he has ever been. It is understandable that he would regress to constructing a Vader-esque identity as the new “emperor of the universe”. It’s like he finds comfort and purpose hiding his emotions behind that mask. And if his mask is has been put back together, with cracks all across it, it is a great visual metaphor for his internal struggle. I think Kylo Ren will appear more evil than he ever has, initially, before his possible redemption occurs.