If the wedding announcement in the newspaper was in the past tense, then the wedding most likely took place. That is, if the article is written as 'The bride wore...' and 'So-and-So was the best man', then this indicates that the event had already happened.
On the other hand, I have seen wedding announcements that begin 'The marriage of Sarah B. and Joseph M. will be solemnized this evening' which indicates that the event hadn't happened yet, perhaps because the article was published in a morning edition of a paper.
Back in those days, the woman would have taken the man's surname, so if she several years later was buried under her maiden name, what I suspect is that the couple divorced, probably fairly soon after the wedding, and so the woman went back to using her maiden surname.
You can also follow what happened to the man over the years, to see if he re-married and when. If he re-married before her death, then they must have gotten divorced. Sometimes, if you can obtain a marriage license for the man, it will state if he had been previously married (at least some US licenses show this). Checking to see if the man had children and when, is another way to figure what his marital history was.
Lock/Lak/Lok and Kalon/Kolon in Zagare/Joniskis/Gruzdziai, Lithuania
Trisinsky/Trushinsky/Sturisky and Leybman in Dotnuva, Lithuania
Olitsky in Alytus, Suwalki, Poland/Lithuania
Gutman/Goodman in Czestochowa, Poland
Lavine/Lev/Lew in Trenton, New Jersey and Lida/Vilna gub., Belarus