Hey @idk_idk,
You’re right that the Procedurally Spawning Foliage tutorial is out of date.
This is a known gap on our side. We track the tutorials that need updating in cesium-unreal#1166, and the procedural foliage one is on that list. I don’t have a firm timeline for it however.
In the meantime, another user worked through the same update recently and got most of it running by swapping in the new method names and adjusting for newer Unreal (for example, the Grid2D Collection emitter setup changed). Their thread is here: Procedural foliage guide outdated?.
I hope this helps at least a little