That's right. Although there are a few pre-rec 'press this buttons', the call usually goes through very quickly. If there is a long wait, 'all operators are busy' comes through. But in any case, calls to the USA are very cheap, something like 5p a minute or less. Even on my mobile, it is 15p a min from the UK.

Remember that even with a Priority Seating reservation, you need to arrive at the designated early time, preferably 10 to 15 minutes before the time they suggest (not the showtime!). Take into account the traffic and parking time before starting out.