Hm! The Wikipedia article intro explicitly lists the Creative Commons share-alike license condition in its list of "notable copyleft licenses", but later says that "any copyleft license is automatically a share-alike license but not the other way around". So at the very least I guess it's debatable :)

(I'm not sure I would rely heavily on Wikipedia for this — they only use secondary sources and in practice most of their sources will be GNU-related, so the article is probably biased in that direction.)