On quilts that I make, I usually add borders.
I've bought a lot of vintage tops on eBay, though and out of the 8 that I can remember, only 2 had borders. One was a narrow 2" border around a brown and peach Drunkard's Path and the other is about a 6" border of yellow around a full-size Dresden Plate appliqued onto white muslin.
The rest of them have no borders - none of them have sashing and cornerstones, either.