During the Splatoon 2 World Championships it was announced that the final splatfest, Final Fest: Splatocalypse, would be taking place from July 18 to July 21st. The theme will be Chaos vs. Order. During the event there will be a brand-new layout for Shifty Station, and the Shifty Station stages from all the previous splatfests will return. There will also be special gear available to participants in the event.
After the Final Splatfest event, update 5.0 will be coming to Splatoon 2. One of the features from the update will be that the Turf War Splatfest will see the return of all 24 Shifty Station maps including the map from the Final Fest.
The final splatfest of the original Splatoon, on Nintendo Wii U, saw the Squid Sisters Callie and Marie pitted against each other. The outcome of that was used as the basis for the main story in Splatoon 2.
At this point it is unknown if there will be a Splatoon 3, and if the results of the Final Fest will be incorporated into a potential story for that game. However, eager fans are already speculating what impact the outcome of this event will be and how it could be used to set the stage for the next game.