I appreciate that [it looks like] we'll have paper brochures for Grand Carnivale this year. If this really does turn out to be the last year of the event then I hope its successor will be as nice and as fun as Carnivale originally was.
I think they've left it very intentionally vague to build hype around it, though I won't be surprised if Kumba's Revenge turns out to be a completely different experience. BGT is in desperate need of a dark ride so I could see something like that using the Kumba theme. I feel like a giga or a (somehow) extended layout is less likely than anything else.
I'll forever be upset that I won't be able to experience Kumba, but in the end it'll be like any other roller coaster whose time has come before I got to ride it.