When they built Fireman's Landing, they put in the infrastructure for a train Track crossing(see photo).
That could easily be used as part of a new pathway to connect Fireman's Landing and Grand Expo. I theorize that they would only claim the southern half of that employee parking lot for this. But if you look at how FM, Frisco Barn and the area left from the Water Boggin and you have the making of a space for a coaster. Other wildcards are RiverFront playhouse and the open air theater and if Valley Road stays.
You might be surprised to know that crossing has actually been there for years. I used it when I worked there a couple of times, but it's main use was when they were building Fireman's Landing it was much easier to bring in the materials that way since they were stored in the lot, and that was the main reason that it was improved- so the construction teams working there during Fireman's Landing build could use it.
There's been lots of speculation that at some point they might use the old employee lot for expansion. The same has been said about the maintanence area around the round house as well, where they could easily build a path from Barn Swing to Fireman's Landing. Or use the gate by Outlaw Run to build out into the woods. Or... :-) Well, I hope you get my drift.
SDC's team didn't win the PR award at the recent Golden Tickets for no reason. If there were plans being formulated or in place, then there would be something coming out from the park in some fashion. Markers, planning teams, "convenient leaks" or something other than wild guess work on a fan forum or from a group of people who are only at the park 3-5 weeks a year instead of the regular employees.
In other words, while I'm sure they have some things in the planning stages for 2020, at this point I'm not optimistic that it's any of those. I have some ideas, and have had a few discussions, but I don't want to add speculation or rumors so I'll refrain until there is something more solid, but don't count on what you think you're seeing or hearing. :-)