It's really just a personal preference and an option we wanted to offer in case you wanted to use it. A little bit depends on how you want to (a) communicate to your members and (b) retain a permanent record for future reference. If members all have different due dates now, the addtional transaction record would provide a specific note of the old and new due date, which might be nice. On the other hand, this will add two more lines of transaction history per loan to everyone's statements! The Tracker note might be enough for your staff to have a permanent record, and then use other methods to communicate to the members. It's up to you!
FYI, if you do elect this option, the description on the $0 memo transaction would be patterned after the following sample:
Primary description: **NEW DATE DATE**
Secondary description: 06/10 DUE DATE CHANGED TO 06/30; NEW MONTHLY DUE DATE WILL BE ON THE 31ST
NOTE: Because of the unique nature of credit cards, this option is not available for due date changes to your credit card products.