I would have to think that if there are droppings in the scrape, that the scrape is not being used as often as it should be, as an active scrape would be cleared of all debris. Of course if the scat is nice & shiny, chances are it was just deposited.
One thing I did just witness during the past scraping period though, was a mature doe urinating about 30 yds from my stand. I know the exact location she relieved herself, to the inch. What was interesting, was that the next morning, I hunted from the same exact stand & noticed that where the doe had urinated, there was now a fresh scrape, that I'm sure had been created the night before. Being that this was early Nov., I got pretty excited. Eventually that morning I spotted a mature buck w/ his nose to the ground app. 50 yds. away. I gently touched the rattle bag & "BOOM" he was there at 20 yds., completly in my shooting lane, broadside. I would like to tell you that the 130" - 8 pointer is at my local taxidermist, but a high hit made for a tracking scenario that didn't pan out in the end. I feel that this buck survived, & I hope to see him again this upcoming season.
The lesson I learned is that all scrapes may not be just a social network, but seems as though they can be made for different reasons. This may explain why some scrapes appear to be random. Maybe they are not random at all. If the doe urine has a slight hint of estrus, I would have to imagine the bucks would go batty, pawing the ground like a raging bull. By the way, I saw 13 different bucks that day. I was there from dawn till dusk, but none of the others were shooters.
I don't think that the scat was intentionally deposited by the deer, but a great sign that deer are visiting your scrape & possibly a good reason to hunt near it.