Keep in mind that Tumbili is part of a greater re-fresh of the old Safari section. It is not really marketed as a totally stand-alone star attraction for 2022. KD keeps pushing the whole Jungle X-pedition makeover, headlining with Tumbili.
With that being said, there could be unexpected delays with construction supplies/materials not being delivered on time; tight labor market for construction tasks yet to be done.
We know that a good chunk of the walkways in that area are being re-done in pavers and they are doing stuff with that former games structure. That Avalanche is getting re-themed. We have not heard anything yet about the revamp of Outer Hanks restaurant and the Congo Thrills gift shop makeover. Plus, marketing keeps telling us that much more is on the way or to come. If there is anything else to all the above; then, KD is holding their cards pretty tight.
If KD cannot get the whole re-vamped area complete by park opening, I can see them delay opening it till later in the spring. That does not mean all of the area would be closed. They could still open the path between the Safari bathrooms and the back of Hungry Hippo for people to get to Stunt Coaster, Anaconda, FOF, and I-305. I assume the impacted areas, still undergoing the makeover, will be blocked off by fences/barriers.
I feel, if KD cannot present the area as they are trying market it, then it will be closed until they can. Plus, the park never stated Jungle X-pedition would be open when the season starts on March 12th.