That wikipedia article is incorrect. The current incarnation of stop loss might date back to the first Gulf War, but my father’s navy service was extended by 6 months because of the Cuban Missile Crisis.
From what I understand, the main difference between this war and others prior to Vietnam is that people find public, media fed complaints about stop loss much more easy to get out there. After all, it’s been an explicit part of the enlistment contract since Vietnam, I think, which as with most “extra” contractual obligations nowadays, means it was merely understood as part and parcel of the draft and only in a wholly volunteer war did it require the man to beat you over the head with it.