Let's see.
20 years ago, they had a buck grunt and a doe bleat. Then I remember seeing a wheeze call, then a snort. Lately they have had success using tending grunts. Oh, they also figured out that doe grunt to one another also. Now the growl.
It's sort of like technology, things are always changing. People are learning new things about animals that they have never seen/heard before. I try not to fall for every new gizmo but sometimes I have to give things a try. Expecially when my close hunting buddies have heard this sound in the woods for the last couple of years. It might not work but I'm willing to give it a shot.