Why do dumpers reach out during no contact?

My ex who discarded me four months ago recently reached out to to see 'how I'm doing', and to wish me a belated happy Christmas.

This was the first of any contact in two months. I indirectly initiated no contact after telling her that I had no interest in being friends with her, and I eventually stopped replying to her breadcrumbs.

I don't understand why she would reach out after a few months to 'check in'. Is this just a question of curiosity on her part?