You may have left already but the greater issues revolve around the nature of the church. It is an isolationist high control group. You (as the non-JW husband) are regarded as either a potential convert or an enemy of God. You seem to be a partial convert, having adopted some of the language but retain language from your past church affiliation.
You are completely justified in being indignant regarding their sectarian isolationism. The extent of the control over the lives of members is not limited to just who they date. All personal decisions are determined by how the church directs. Your son is exercising independence, that is what is most deeply disturbing to your wife, it is an alarm bell for those fully invested in the church. He is probably already being marked by other youths in the congregation as 'bad association'.
This social distancing can be very powerful in compelling members to conform. If you find the sectarian isolation a concern you might express that to your son.
Let him know that you will love him regardless his religious choices in life.