That is not in the Bill. Indeed, the Government have said that it is entirely a matter for the Crown, in the double sense of the monarch and the monarch’s Ministers, who might have a role in advising the monarch.
Incidentally, I would not want to be a monarch apart from Elizabeth with a “II” in my title, but when James II was removed, Parliament decided, through the Bill of Rights and then the Act of Settlement, to hand over a joint monarchy to William and Mary rather than to anybody else. Then, when the Stuart line was going to end with Queen Anne, Parliament decided how the succession should proceed. Again, when Edward VIII tried to abdicate in 1936, the abdication could be allowed only because there was a statute of Parliament the next day.