As has been mentioned, the original talk was named "Millions Now Living May Not Die" but later handbills were changed to "Millions Now Living Will Not Die". The latter phrase became the official title and campaign for decades afterwards.
So technically speaking, this WT article is correct. The talk in 1918 was named "...May...", though they conveniently leave out any reference to the changeover.
I do find it interesting that they actually show a handbill with the later phrase. If they were really looking to re-write their history, I don't think they would have included this photo. I don't think there is any sinister plan here. They're probably confident that most loyal dubs aren't going to even notice the difference. I'm sure that they're confident that they won't even dare question it.
Which is being over confident. This is the kind of thing that makes people take notice. If you're sitting in the KH in February 2010, trying to stay awake through another brain numbing WT study and you spend an inordinate amount of time studying the old photos to kill some time (which I liked to do when I was still in), this might be something that makes some people question. If you're paying attention at all, you have to wonder, "if they said in 1918 millions living will not die, yet here we are almost 100 years later...there can't be millions left to be alive..."