So the rumors about the next series going all out are true, and RRR Otoku has a translated interview from Hyper Hobby magazine to prove it. Turns out that Toei found out that it was too much work to edit the entire Great Legend War scene from Gokaiger, and decided to film an entire new sequence to fit the setting of Power Rangers.
Now the interview said nothing about the next series having to do with pirates, just that the next one is going to feature every single Power Ranger. It could end up making Goseiger into Power Ranger's anniversary series, utilize Gokaiger as a mid season upgrade, or they will skip Goseiger and do Gokaiger instead. The tides are open for what the next series is going to be about, and it might result in more original footage by Toei or the people at Saban.
Whatever they do with the next series is fine by me, because I have a feeling that it's going to be a fully original story. Based on different receptions I have heard from people I know, the best Power Rangers series tend to be the ones that are completely different from the original or 90% close to the Sentai counterpart. If it fails to comply to one of the two requirements, then it ends up being a terrible or decent show. Saban has the chance to hit a home run next year, and it might get older fans to return to the franchise again.