Are there any episodes of Digimon that weren't dubbed to English?
There is no OVA, all you get is a narrated flashback.

In season 2 ep 27 Izzy tells the new Digidestined about how the original eight went to the Digital World and spoke with Jeni. Jeni instructed them to, "release the powers that protect the Digital World". This meant releasing the powers of the crests, from within themselves, in order the defeat the darkness and spread, "a coating of goodness" over the world. This brought peace and beauty to the Digital World.

Even though the crests were destroyed, the power of the crests still remained inside of the Digidestined. It was that power that was released.