I wouldn't be surprised if 2027 ends up being an off-year for the park, or some very minor addition(s)/refurbishments. Kings Island has added new family attractions for the past four seasons in a row, plus Six Flags already has several 2027 projects in the works for other parks in the chain. I highly doubt we're going to see anything like a Vortex replacement or other significant coaster built for 2027. Although, I do have some ideas of what the park could add (if they decide to add anything at all)
Begin a retheme of Action Zone: I imagine this would likely be a multi-year expansion project similar to Jungle Xpedition at Kings Dominion. The first phase would be rather minor, focusing on ride and restaurant rethemes. It's also possible we could see some sort of flat ride being added.
Rivertown: To be specific, the pathway between the Eiffel Tower and Rivertown where the Shooting Star cafe is. I could see this being a good area to do another flat ride package similar to Adventure Port.
Front gate: Refurbish the front gate plaza and the facade of the front gate to be more modern and welcoming to park guests.
Soak City: Although Soak City has recently recieved new additions in 2025, they still have land to do some more expansion if they really wanted to.