Ana, what you have posted is a very strict interpretation of how it can work.
The opt out allowance (utilities/accommodation/call it what you will) has been delayed in the past but I don't think I've ever met anybody who has wanted it and been unable to get it. Occasionally (very occasionally) the accommodation department has said they won't process any more requests until, say, August. I don't know if this has been because of a shortage of staff or a surplus of accommodation but the trick would appear to be to ask them before you sign anything.
I moved out over 10 years ago and following various housing fiascos have never regretted it. If I hadn't I'm sure I would be divorced by now.