It's not "dead", it's just not a focal point. If it were dead, nvlink wouldn't be on brand new cards. What is dead is a physical bridge on AMD cards, they no longer "need" them (not sure how accurate that is in regards to "need", but regardless, they don't have them). I don't know if they are only supported on specific cards, or all GCN 3.0 (maybe 2.0?) cards support it.