I’m not convinced she will. I’ve always thought she should have but never I believed she would. She just never does. I think she will either confirm it by her actions (I hope this never happen!) or just stop hanging out with him and hopefully allow us to forget him peacefully. It’s been a few weeks now, and I’m starting to forget him already, so I hope it stays like that.
The only situation that would require her to address the rumor is if she has a part in The Crown. In my opinion, if this rumor is still alive when it’s announced, she will need to clarify her relationship with the creator of the show if she wants to avoid bad press.