I've had girls disappear before, but I had built up a close friendship with this one. One day she told me she wanted to move it to a romantic relationship. Two weeks later, ghosted. I feel more like I lost my buddy really, and it's worse. If she was just some girl I dated for awhile, I probably wouldn't care. I look at it this way, she probably has some issues she has kept to her self, and she is going to need a long time to work it out. Probably the same as your guy. I'll move on, and hope the best for her.
Ultimately, when people do this especially after getting close to someone- shows a problem with themselves that needs to be worked on and resolved. And like you, I hope and pray the best for him.