Mr. Burke’s appointment as director of the Holy See Press Office was surprising for many reasons, but none more than the fact that he never showed any great enthusiasm for Pope Francis or his vision for the Church. Burke has admitted that he hesitated to accept the position. But because of his loyalty to the Church and out of obedience to his Opus Dei superiors, he took the job. [...]

But celibate members of Opus Dei (numeraries) cannot just quit high-profile positions without consultation with and approval from their superiors. This would have to have been a decision Mr. Burke took only after such consultation.
And it would not have been arrived at easily. The personal prelature puts high value on having its members in key positions in the Church and society.