FYI (if this wasn't posted elsewhere), I called into DCL and it appears that they've extended out the applicability of onboard booking discounts made in 2019 until September 21, 2022. Our onboard booking discount originally would have expired in early September 2021. This means that everyone currently holding an onboard booking discount should be able to switch the discount to any of the new itineraries opening tomorrow, but I'd call into Disney to be sure.