Examples of articles using ADL as a source: this this this and this

Check my explanation and in particular the link I gave, it explains a little bit more. The OP article is just a little confused about how Wikipedia works. Actually, down near the bottom, they get a lot bit closer to how it works:

By deeming the ADL “generally unreliable,” Wikipedia is telling users that “the source should normally not be used, and it should never be used for information about a living person.” Wikipedia is not poised ban the ADL outright; enough editors have argued that some aspects of the ADL’s work, such as its database of hate symbols, should still be considered an acceptable source.

That’s actually a lot closer to what happened than is the headline or the early part of the article.