Even if we forget this whole concrete bollocks, how much does it even matter? It's not even in Phantasialand's interest to open Rookburgh this season, they're still getting Loveparade-esque attendance (greetings from Duisburg) just from Klugheim alone, while still spending tens of millions every offseason on improving everything that's already there. There's just not a single reason to veer away from the 3-year-investment-cycle right now.
Let's look at this economically, currently they're charging 47,50 € for single-day admission. If they happened to open up Rookburgh, that price is for sure going up, which means they would both crack the 50-bucks-mark (which is an important psychological border especially for pulling families into the park) and become more expensive than Europa Park, while only offering like half as many attractions. That's just not a very smart thing to do, and since they're pretty much stuck on their yearly attendance figures for ~8 years now, all their financial potential comes from their entrance fees, so I bet your ass they're being extremely careful with that to not screw it up.
Oh yeah, and I also mentioned a 3-year-investment-cycle above, you have to factor in that Phantasia's 3-year-investments exceed basically every existing investment-cycle of any theme-park. Let's say they open Rookburgh in 2019, what's next? According to the current rumours, China. If they were to revamp Geister-Rikscha, that would therefore count as a "smaller" investment, since I don't believe that would fall into this big cycle. But let's look at other parks, who refurbished or built somewhat similar attractions to that: Efteling with Symbolica. With a 35-million-euro price tag their heftiest investment to date. And I can tell you already, that will be exactly the kind of standard, Phantasia will be aiming at once Geister Rikscha ends up on the chopping block. Maybe they wont be pissing on Symbolica (maybe they even go for a totally different style of darkride or even a completely different ride) but does anyone in here seriously believe that the replacement will be considerably subpar?
So maybe we just all calm down a little and let them take their time with Rookburgh because it probably costs more than the entire street you're living at.