Stub as in Wikipedia's usage is where they shotgun-create loads of minimal skeleton pages that will hopefully be filled in with details later. I don't like Stummel so well. Kontrollabschnitt is close perhaps. Wikipedia.de uses Lückenhaft which sounds kludge, IMHO. Ideas?
I don't know what other people call it, but I refer to stubs that contain a skeleton structure and predefined text blocks (Textbausteine) as Textgerüst or simply Gerüst.
It's hard to tell which meaning of "stub" was meant when someone decided to use it for a minimal article, but my best guess it's taken from programming (especially top-down) where stub is a non-functioning function/subroutine/class that consists of a declaration with no actual code. Basically, in order to write the upper level code before taking care of the lower level code, you have to "stub-in" these empty declarations to keep the compiler happy so you can get something you can execute and test. If so, then apparently the German term for this is simply stub; see de.Wikipedia But I don't think "stub" is a particularly good match for the Wikipedia meaning, I imagine that someone decided a bit of jargon was needed and the word fit no worse than other possible choices. So given that jargon words are somewhat arbitrary, I don't see that Lückenhaft as a bad choice. In any case, once jargon becomes widely used by the community it's pretty much set in stone; the effort and disruption involved in changing it would far outweigh any possible benefit.
Rudiment or rudimentär seem fitting, this is used in software development in a comparable sense: "Feature xy wurde bisher nur rudimentär umgesetzt, eine bessere Implementation folgt in Version z."
Maybe Bruchstück or bruchstückhaft, which is often used for something incomplete, although in a literal sense, "Bruchstück" suggests a part of something that was whole before. which isn't a good fit.
Ansatz comes to mind, too. Anfang would be an even more optimistic take: "Dieser Artikel ist nur ein Ansatz/Anfang."
Lückenhaft does seem usable to me, but that would be more fitting for an article that has weaknesses and missing pieces in some aspects, not so much a very short one.
"Stummel" and "Kontrollabschnitt" don't work at all, as @tofro already stated.
"Rumpf" works, but what I don't find perfect about it is that "Rumpf" (hull, trunk, torso), like "lückenhaft", suggests that the main part is already done and only some additional aspects are needed.
For Wikipedia articles, the anglicism Stub fits best. But it could be translated as:
In general, you could call a place-holder/marker waiting for further development metaphorically Baustelle:
Der Text ist noch eine Baustelle.
Or you could say:
Der Artikel ist unfertig.
Both convey the very concept that the current state of the work needs to be amended while the main sections might already be finished.
Skelett is also possible, but sounds quite technical/anatomical. The metaphor is similar to Baustelle.
Der Text ist (noch) ein Skelett (or: Textskelett).
You are asking us to come up with a word that doesn't exist in German.
Languages often use different linguistic constructs to express the same concept. In this case, what corresponds to the English word stub is best expressed using an adjective-noun phrase such as "unvollständiger Artikel".
The propositions in the other answers are neologisms and won't be understood out of context. I don't know what a "Textgerüst" or an "Artikelrumpf" are.
Personally I think that Wikipedians should decide what they want to call the differents functions of Wikipedia. People there are just as knowledgeable about German as we are. Why don't you open a discussion there?