No, "when" would be hard to predict. I believe miners will have a tendency to become fickle once BU reaches almost 50%. They realize that the future of Bitcoin is hanging in the balance and as humans we usually do not want to break the status quo. I am not 100% sure but maybe one of the mining pools could back track and support Core again.
Thank you very much for the clarification.
I would also want to say that you should not take my word for it. What I posted is only a personal opinion and I could be wrong like sometimes in the forum. There are other members who know more than me like Lauda and franky1.