Not sure if this is a mislabeling or wrong counters being incremented, but running a WT test, I see this in serverStatus:

		"MMAPV1Journal" : {
			"acquireCount" : {
				"r" : NumberLong(8),
				"w" : NumberLong(28760)
			}
		},

I see it in server status outputs going back to pre rc9, but until this run I've never seen it go up.