I don't understand why government staffers would do this.
More generally, the problem with Romney is not so much what he says, but that you can't believe him. It's possible that he could explain a dramatic conversion event, as some of the former abortion-business workers have done, that would convincingly display a personal commitment to protecting human life.
However, to the best of my knowledge, he has not done this.
Myth's "conversion" to pro-life directly coincided with his decision to run for president four years ago. It was a claim he made for expediency and nothing else.
As you mentioned, there have been plenty of abortionists who have converted to pro-life; however, they have always spoken of some catharsis that occurred.
Imho, he is obsessed with becoming president. If he is going to run as a Republican, it’s a benefit to him to proclaim himself to be pro-life.