Yes. It means that you can make ADRs starting at 90 days from the day of your check in, plus for ten consecutive days after that. You call and say, for MOnday, Tuesday, Wednesday, etc… It helps to do it all in one phone call.
If you are staying for 14 days, you would have to wait to call back to do those other 4 days. This only applies if you are staying on property. If not, you would have to call back for every reservation at 90 days, or a phone call for every day that you are staying at the parks (one week=7 phone calls). Does that help? It really is a perk for people staying on site. With the new reservation system, they can actually see if you are staying where you say you are staying.