Their sexual orientation probably would not change when they decided to become celibate. It wouldn't change if they decided to become vegetarian, enter a monastery, or marry a woman. It could change if they decided to accept Christ as their Saviour and were baptized with the Holy Spirit. There is not more evidence of this kind of change because people who experience it are mortified by their previous homosexual debauchery. They are thoroughly ashamed of their past life; consequently, they do not talk about it. People who enter xgay ministry, in general, are making a big mistake. They should be smiting their chests and asking God for mercy, not parading themselves around like a queen, telling others how to be Christians. SDA, for some reason have a penchant for from "trash to treasure" testimonies. They like to hear about the degradation and defilement others have passed through. Not only x gays. Former drug abusers, criminals, adulteresses and adulterers, all like to get their time in the SDA limelight. People are entertained by pastor's wives telling about their affairs with academy teachers, criminals telling their stories of illegal behavior, disrespectful children going on about the shame they brought to their parents, alcoholics rolling around in their vomit, all this before they got "saved."
Tales like this appeal to a certain class of people who make up a good part of those who join the denomination. An acquaintance of mine, a physician, told me about his Christian pastor who was a physician in Viet Nam, fled the country, was a refugee, and then repeated medical school in America to continue practicing medicine. Both he and his wife, also a well educated professional, appreciated that kind of testimony. They would be appalled by the stories that some SDA "converts" trade in. They don't want to hear about a guy who sold his rear end on street corners.