I'd say that Sunak can wait to see if/when public opinion turns to genuine anger that Braverman asked the civil service to give her an option not available to the general public (one rule for them etc), then sack her for that rather than either allowing her to resign on principal about immigration (and give her leadership bid a nice boost), or (even better for her) be sacked for saying/doing something insane on immigration.
I'd say that Sunak can wait to see if/when public opinion turns to genuine anger that Braverman asked the civil service to give her an option not available to the general public (one rule for them etc), then sack her for that rather than either allowing her to resign on principal about immigration (and give her leadership bid a nice boost), or (even better for her) be sacked for saying/doing something insane on immigration.