Yes, it’s a test, but not a religious test. Whether someone believes (based on medical evidence) that homosexuality is a medically healthy practice or not, is not inherently “religious” idea. It is, though, inherently a physiological/medical idea, since the reasoning behind the nominee’s position is based on physiology.
In any event, from what I’ve heard, the nominee doesn’t believe in discriminating against homosexuals. For him, it’s purely an issue of which practices are more or less healthy. He’s not using his medical conclusions to, for instance, deny homosexuals health care or hospital visitation rights (via same-sex marriage).