Beneficiary On Ex-husband's Life Ins And 401k

Location: Tennessee

Backstory: Divorced my husband last August for serious alcoholism. He never got sober and died suddenly in March. He left no will so his adult son inherits everything(we had no kids together). We are still very close and he was asking me about his Dad's life insurance, burial insurance, banking, etc. About 5 years before we divorced we both started new jobs and put each other down as beneficiaries on life insurance and 401k. I changed my beneficiary info after the divorce. In the last few months, my ex wasn't paying his bills - physically too drunk to - so I don't know if he ever changed his beneficiary info.

The ex in-laws dropped a bombshell on my stepson last week that my ex has another adult son they knew about but told no one. I knew nothing about him either and after 20+ years together, if they had a relationship I would have known. They did say that my ex wasn't listed on the birth certificate. They wanted my stepson to know in case the other person comes forward to file a claim of inheritance. My ex left a list of things he wanted peple to have (material items of significant monetary value). I am on that list but it is just something he wrote up near the end so not legal. This unknown son is not mentioned on that list. I have zero desire to fight the estate or my stepson for anything. The estate has quite a bit of value so I fear it might get ugly for my stepson.

Before anything heats up with this mess, my question is: can I (or my attorney) call his employer and ask about the beneficiary? Or, in Tennessee, does the divorce automatically remove ex-spouses? If I am still the beneficiary can this other unknown son contest it? I received a very decent divorce settlement so I'm not worried about the amount or anything like that, but if I am still the beneficiary I want to know before I get dragged into the chaos.