It sounds like he wants to do Exploratory with a Scope first to see for sure if the Surgery is needed or not.
Hopefully he's a good Doc and will make a good call. Usually a good Doc will not do Exploratory on the Shoulder unless he thinks you most likely need Surgery.
The thing is that by what I've learned about Shoulder tears is that unfortunately if the tear is that bad then Surgery is needed and will repair it. If it's small enough it CAN heal on it's own.
It's basically like getting stitches so that the wound can heal closed up, except the wound is inside on a large Tendon.
I would wait and see what he says after the Exploratory. And ask to see the MRI's yourself.