I do not believe that. I believe the soul can exist independent of the body.Once the body dies, the spirit or energy has nothing to "keep it alive" so when the body goes so does the spirit (or soul if one wills).
The soul is not dependent upon the body to survive, the body is dependent upon the soul to survive.I would ask how the soul is dependent on the body to survive if when the body dies, the soul does not. If the soul is paramount to one's spiritual survival, it would make sense that the body wouldn't "hold down" the soul.
The soul only needs the body to express itself in the physical world, but when we are no longer IN the physical world, the soul expresses itself in a spiritual body in the spiritual world.
Since the soul is a mystery, we cannot describe it. We can only know its function because of what Baha'u'llah revealed.Most say it's a mystery or choose not to describe it for whatever reason. If it's a mystery, etc then it would be hard to even suggest it's existence without some core characteristics that differentiates it from what I mentioned above.