I still believe that F.L.Y. and Klugheim with it's green wall are part of a greater 10-year-ish plan of Phantasialand including a new entrance and a theme-hotel in the Berlin area including the Obstwiesen, which leads me to believe that Geister Rikscha would be an absolutely fitting candidate for the chopping block, as it's "renewal" allows to bypass the time it will take to just work on the things I stated above.
The China Area is already in an ongoing transformation into a more generalized Asia area, same with Mystery where River Quest supposedly will get a new entrance next season. All of these things are wink wink nudge nudges towards a removal of the weird/undersized entrances back there imo. In a sense of "we're redoing these areas anyway".
Geister Rikscha would not require the entire China area to be closed off. It's well known that Phantasialand is not happy with Colorado's entrance, and if you relocate it somehow, it would be pretty easy to make the then unused path accessible for construction vehicles. Especially all the work they put into Ling Bao recently does not suggest that they plan on leaving the park without the chinese area for some time.
On the other hand, Fantasy is still the ****hole of the park, in a sense of: they've put in a lot of good effort, but it didn't pay off. The newer flat-rides all do look very good and Wuze Town is fantastic (even though the kids area on the upper floor is in such a weird location that most people have never seen it), but the Mondsee is completely unusable thanks to the neighbours, and the overall situation made Phantasia stop the transformation/renovation of Fantasy halfway, as it seems like they will have to come up with an entirely new concept if they are looking to Make Fantasy Great Again™. The area is huge for Phantasia's standards and it's not just the Temple complex that requires a renewal. Wakobato has never operated in it's intended state, and considering how all of their efforts of improving it have been half assed, I believe they already have given up this battle. It would also be uncertain where Fantissima would go during construction.
No, my final stance is that Fantasy is way too big of an issue to be next on the chopping block. All the rides operate well, some of them are just not matching Phantasialand's current aesthetic standards. Just take noise mitigation as an example. The Temple would certainly get an entirely new building as the old one is toast, and then you still haven't covered the Mondsee, which is way too large to just be left abandoned. So you'd have to come up with a concept, that covers an area ~3-4 times as large as Klugheim while still providing an acceptable view for the neighbours. I'm convinced that Phantasialand can and will do exactly this, but this is a 10-year-project. There's a good reason they've put Temple as far behind on the schedule as possible.
The timeline as I currently expect it:
2019: Geister Rikscha closing, F.L.Y. opening, new River Quest entrance
2020: off year, as I expect the replacement of Geister Rikscha to take quite some time. They can afford it, and as an underground darkride, it's actually not the easiest construction site to work with. Possibly some refreshments to Feng Ju Palace (the attraction is fine, just needs someone to blow the dust off).
2021: sick Geister Rikscha replacement courtesy of ETF Ride Systems. Better integration of Mystery Castle into the rest of Mystery and Klugheim (including renewed effects inside the attraction) as a preparation for closing the Mystery entrance. Construction starting on the Obstwiesen.
2022: New main entrance and Berlin hotel making use of the Obstwiesen-area.
2023~2028: complete overhaul of Fantasy
All just speculation and my unworthy opinion, but it adds up quite nicely in my head.