No worries, I just wanted to clarify because misinformation helps no one.
The website is incorrect, that is simply not the policy any more as far as I know. You can choose to live off campus for any reason now. When I was in 1st (almost 2 years ago) the policy as you found it was the policy in effect and if you told them you HAD to bring a pet or have family or a significant other coming with you were allowed to live off campus. I lived directly off campus because my start date was bumped up one semester sooner only like 3 weeks before the start date so there was no more space in the dorms - my entire orientation group was individuals who were living off campus and half of them were off campus simply because they had pets that they could not or refused to leave home for one semester.
As of a year ago that is no longer the policy and you can notify them that you are not living on campus. I know this to be fact because for one, two of my friends came to Ross a year ago and lived with me (off campus) in their first semester with no issue at all (that was the first semester you could opt out of on campus) and also because I have been an orientation leader multiple times so I am particularly up to date on the rules surrounding housing because those are the questions that new students are constantly asking during orientation. I wouldn't put too much stock in the fact that you found that line on the website because God only knows how often they update it. I was just looking for one of my surgery professors on the faculty list on the website and she's not even listed at all even though she has been teaching here for over 5 years.
If they have made changes reverting these rules back to requiring people to live on campus they have not notified any of us who are here at Ross, which would be unusual because there is generally a campus-wide email regarding any policy change. I really can't see the 2 semester thing being real because there just aren't enough dorms to house two entire classes worth of students at one time.