I think the closest we’ve come to verification is “believed to be” his voice on tape.
I think it is more than reasonable to speculate that those on the hunt for him may be privy to other information confirming him alive....outside of that which is known to the general public / media. Just as this was true of Zarqawi in Iraq (one who was most certainly alive for years in Iraq causing chaos, yet never put himself out on video to be seen).