CPs are not required to take classes. There are classes that Disney offers to the CPs and if they would like they can make arrangements for those classes to provide college credit, however it is up to the individual to make the necessary arrangements and coordinate with their college/university.
The PIs do not have these classes. However, as part of your on job training you may be required to take classes (not similar to the ones offered to the CPs) These classes cannot be transferred for college credit as they are considered OJT.
**Please note, this may vary for some PIs however, this information should apply as a general rule.