I am sure they will give you plenty of notification of your start date, as you will probably have to give notice to your current employer. however, if your start date is before your holiday, then they probably wont authorise you time off for your holiday (unless they have already agreed to this at interview).
And yes, sometimes people are in holding pools for years. You shouldn't have to reapply for the job unless you pull out for some reason. what airline is it for? People who work for that particular airline may know more information about waiting times in the holding pool, holidays etc.