The article says "temporary visas", not visa waivers. It also says "They had already been granted employment authorization". But I agree more details would be helpful.
It's extremely unlikely a journalist this haphazard is going to differentiate between a visa waiver and a temporary visa. Obviously some came on other visa if they could work, but it doesn't matter anyway; any non-immigrant visa you enter with will include the requirement that you have no intent to immigrate.
The only options are to be lucky enough to have decided to get married and immigrate after you were already in the US, or to do the application from overseas.
