Threading the gap between @DaptoFunlandGuy and @joz here - in poker terms, I don't think you want to show your hand, nor do I think you fold and show nothing. I think you just need to have a plan and continue to have a conversation about it. No "ooohhh masterplan coming soon" and no "here's Atlantis... loljks." Disney as per usual does well in leading the pack in having a plan, drip-feeding a project, letting the project open and succeed, and then moving on to the next project.
In the case of Dreamworld, i'd have the next five years mapped out with five key milestone projects (coaster, ride, family, slide etc.) and literally just say "we have a ride coming every year for the next five years!" and then drip feed the milestones out. 11 months out, here's the concept art for ride #1. 8 months out, here are the facts and a first look. 6-2 months out, here's construction, get excited. 2 months out, here's the ride in action. <1 Month out, get your tickets, we're doing a launch party, woo. Then let the ride do it's thing all summer, then come February after the holidays, rinse and repeat for ride #2. Interlace with a bunch of seasonal events that you're constantly building upon year over year, and you've got yourself a money-making machine and a way out of the post-2016 hole.
It's why Disney parks will do up a scaff with a fake castle print overlay when they're working on the castle. My biggest gripe with our parks, and it's a line i've beaten to death now, is that whatever succeeds something should be better, no exceptions. Our parks (all of them) fall short of that mark quite regularly. You only need to look at Village's new signs to know that we take steps backwards everyday. Disney is Disney because they're forever adding and plussing things, and, eventually, that becomes an experience that's greater than the sum of the parts. Disneyland's opening facades were fractionally better than Dreamworld's opening day facades, and over the 7 decades since, they've continually refurbished, touched up and added to them, and now they're epic. Dreamworld has constantly been a case of slowly removing, whether it's been smaller touches like colourscape, flower boxes or big touches like replacing custom-carved old doors with glass sliding doors or entire facades for Abu Dhabi Airport. Keep cutting some more, no barbershop quartet, no sound of a steam train in the distance, add a modern roof down one end, add a LEGO store in the corner with a bunch of white walls....
I feel like i've been waiting for over a decade for that to feel true with Dreamworld. Same for Sea World currently too. The removal of the chairlifts and the SBNO'ness of the Log Flume really makes it obvious.