You can purchase the Fortnite OG Chapter 1 Season 2 Battle Pass from the Item Shop. Alternatively, if you have an active Crew subscription, you will get it for free. This new phase of the storyline ...
According to the Fortnite leaker ShiinaBR, the next major phase of the storyline could be created using UEFN (Unreal Editor for Fortnite). This would be a shift in how seasonal content is created.