Both CUNY, SUNY and most private nursing programs as well have only a finite number of slots for each incoming class, that is the cut off point for that particular entry class. Once that number is reached the remaining applicants have a few options: they can remain at said school continuing to take other required (but non-nursing) courses and reapply for the next entry class, or pick up sticks and transfer to another school in hopes of getting in there.
Using Hunter-Bellevue's "generic" undergrad BSN program as an example:
To enter Hunter's upper division and be accepted into the nursing program one must complete the two year pre-nursing sequence and take the NLN pre-nursing exam. To determine ranking of applicants half one's score is taken from the NLN exam and the other half one's GPA from the pre-nursing sequence.
Hunter-Bellevue like most CUNY schools requires a minimum GPA of 3.0 in the pre-nursing sequence, but the average is much higher at 3.5 and indeed some classes nearly 3.8 to 4.0. Then there is one's composite score from the NLN (usually ranges from about the 130's to 150's on average based upon a quick research of those claiming admission). As stated previously Hunter then takes half of each score to make up a new number and assigns ranking of all applicants according to this score.
HB only takes 100 students each Fall so depending upon where the axe fell someone with the GPA/NLN scores may have been the 105th or even 101st, it all depends upon the strength of the applicant pool for each class.
One thing about "waiting" once one has completed the pre-nursing sequence and taken the NLN that is that and those are the only scores that will be used should one apply again. Unless that is a program will accept the better of several NLN scores, but still one's GPA is what it is and taking furhter non-nursing classes does not count for admission purposes. So in theory one can sit around waiting one, two or more semesters without any firm promise of being admitted.
IIRC some private nursing schools do have an official wait list. That is they will place a number of students who didn't make the cut on the first round onto a list to be called if anyone what was admitted drops out before the class starts.