There are a number of Jet University students that have completed the program but are not 21. Those students can not be hired by Pinnacle until they are 21. This is not a new requirement. It has been in the FAR's the whole time.
The problem is that these under 21 students did not find out about this until they had paid their money and completed their training at Jet University. However, these students were guaranteed First Officer jobs in their contracts.
You must be at least 21 years old to sit and take the ATP written. This is because the ATP written expires 2 years from the time you take it and you must be at least 23 to receive an ATP rating.
This is covered in 61.35(a)(2)(iii) of the FARs which says:
Pinnacle requires that all First Officers pass the ATP prior to being employed by the airline. This is not a new requirement. The folks in management at Jet University are attempting to say that Pinnacle has changed the rules. This is simply not true.