If it's got anything to do with stress micro-fractures, it's the result and not a precursor. Bone edema doesn't cause the micro-fractures, or show up in advance. It's the body's response to them.
The doctor diagnosed "significant bony edema". A doctor doesn't choose those words by accident, and it won't be something that has been there his whole life. He may have been playing with stress injury in the ankle for a while, but "significant bony edema" isn't congenital. The treatment for stress injury is rest. Not reduced playing time, rest. Don't let it heal all the way, and it will flare back up before you know it.
He could have ligament/tendon problems that could cause bone edema, but that would mean he's courting some of the same problems Tim has had. Or he could have had a deep bruise that crushed some bone fibers, and caused edema. The solution for both of those (assuming it isn't permanent damage) is the same - rest. He could have cartilage damage that lets bone rub on bone, and has caused edema. Rest won't fix that, but it will let the bone injury heal.
Significant bone edema - he needs to be off the court and in a boot. The rest of the yammer is pure horse and a waste of time. If they get him back on the NT this season, they're playing with his future there as well as here. Rest is not a punishment.