What did this person mean about being Jewish?

I talked to someone on the phone today for the first time and he had a very unique name and I said “oh is that Arabic” and he said “no it’s Hebrew” and I asked if he was Jewish and he said “not anymore, but it depends on who you ask.” I didn’t want to pry any further cause that seemed personal but I was just wondering what that means? Does that mean he got excommunicated?