They are kept intentionally vague. They can be found around Siptah, partaking in any of the new or revised activities, as exploration rewards and so on.
We want you all to go out, explore and participate in what’s new on Siptah.
If still in need of more precise information, we’re sure our wiki masterminds will get that information on paper soon, or any of our content creators will have a highlight of the new stuff for those of you who don’t mind the spoilers (we heard there’s a camps location highlight video already out, by @Pixelcave 
).
New content for the Exiled lands has been pinpointed on where to find it, however.