I'm not on Twitter nor have I ever heard of Safari Mike, but for what it's worth, I heard about the potential of this happening more than a month before that tweet. When I first heard about it, both Heimlich's Chew Chew Train and Francis's Lady Bug Boogie were expected to make the move to the Planet Watch area, but I haven't heard much about it since then. It was discussed briefly in the Pixar Pier thread in the DL section of the boards:
As I discussed in that thread, the claim that this is being done for financial reasons doesn't make sense to me. With Disney's bloated design and construction costs, the parts that could be reused would be a negligible amount (likely less than 10%) of the budget to reconfigure, relocate, and reinstall them, and they'd have the disadvantage of many years of wear and tear. There are plenty of reasons to add new attractions to DAK, but doing it simply because there are some old ride vehicles laying around isn't a very compelling one.
It's an idea that only makes sense on paper to someone with very little real-world experience. It's such a strange idea that it actually fits right in with Disney's current approach to the parks.