Blooloop just released an article mentioning that the chain is looking to purchase some properties in the US close to their existing parks, to create synergy and a stronger local base. The goal is not only to increase revenue and attendance for the chain, but mainly to increase membership rates, which will provide a more stable revenue source for the chain.
This news is coming off another great year for the company, as they have reached record numbers yet again. Gone are the days of financial woes. Six Flags has worked their way back up to a fierce competitor in the industry. They are expanding overseas again, and seem to be much better off than in the mid-2000s.
So what parks could they possibly acquire? I'm going to use Waterworld in Concord, CA as an example. Six Flags recently entered an agreement with the park to lease and operate it. They rebranded it to Hurricane Harbor, and control the day-to-day operations more so than financials. So Six Flags makes the revenue, and basically just rents out the park rather than dealing with ownership. They may target smaller parks around the country to do the same.
Six Flags would essentially come in, run the parks to make profit for themselves and the owner, and not have to deal with shelling out huge money to own the land. At this point, I don't see the chain spending hundreds of millions of dollars to buy mid-large size parks, but they definitely can use leasing as an attractive option.
Others have also pointed to the chain reacquiring parks formerly owned by the chain, but sold due to financial problems. This includes parks like Darien Lake, Elitch Gardens, and Wild Waves. While the parks' demographics do fit the chain's targets, all of these parks (besides Elitch, owned separately) just entered new ownership with EPR Properties, and a long-term lease with Premier Parks. So it would take a lot of money and convincing to break those deals.
So all in all, I wouldn't expect to see Six Flags acquiring the Busch Parks or similar big box parks. But if it means acquiring a smaller park or water park close to a major property, that is definitely a possibility to try and increase membership rates. It's just really hard to think of many examples of this right now...