What Really Happened when Neo Left?

Hey Does anyone kno what happened when Neo Left The Acatec

Did all the Door Get Destoryed.

But I thought that Matrix was going to be Destoryed once he left.

Neo is seen walking towards the door leading back to the matrix, I find it interesting that he isn't seen walking through the door. We can only speculate. Also, someone I know believes that Neo went to both doors. The two door theory doesn't make sence to me, but I think all the doors were destroyed.