Okay, I think what's happening is that there's confusion between Platinum and Premier. I think
@Aron1012 meant the Platinum pass all along, and
@ScubaCat thought I was talking about the Platinum pass , meanwhile I had no idea there was such thing as a Platinum pass

To answer the question, I put a list of the APs below. The difference between
Platinum and Gold appears to be just blackout dates, but
Platinum Plus has more perks. Here's a link that compares all of the WDW-Specific passes:
https://disneyworld.disney.go.com/florida-residents/passholder-program/
WDW Annual Passes are:
Platinum Plus
Platinum
Gold*
Silver*
Weekdapy Select*
Epcot after 4*
*For Florida residents only, blackout dates apply.
Premier Passport:
Access to Disneyland, California Adventure, all WDW parks - no blackouts