I've seen records with and without the information, and I think it depends on which document has been transcribed and what county & state it is from. It seems like some of the counties in N. Carolina and Indiana don't include as much information as other counties and/or states.
I also notice that the same record is transcribed more than once in the same collection.
I'm not sure if FamilySearch is limiting the amount of data, or if it's just a matter of which collection you're viewing, but I've also noticed that the portion of the citation that says "citing [page, line, etc] " is not available for some of the marriage records.