Your link doesn't lead anywhere that has anything to do with Dark Dungeons.
And yeah, coincidence. The original tract was of course part of the actual Satanic panic back in the day. The movie was intended as a satire of the tract.
Fixed the above link - YouTube's version of the same trailer.
As for "coincidence", just because it's a satire doesn't mean it wouldn't have signified a similar zeitgeist. It's kind of a "goose/gander" situation, now as then.