My answer would be "sometimes"
I was the only person who voted "no" to the poll, but only because there wasn't a "sometimes" option. While I absolutely love the idea of lions hunting in prides, they don't always hunt in prides. They hunt in prides when they take down larger animals for strength, and occasionally hunt in prides for smaller, swifter animals to confuse them.
So, in my opinion, if they were going to add this to an update, I would ask that the lions occasionally hunt in prides to take down large animals like Bears, Cave Bears, and Mammoths but I would suggest leaving the smaller animals to fend for themselves.
The reason I say this is because a large animal like a Cave Bear or Mammoth would present the same amount of danger as 2-3 lions, so if you want to hunt that mammoth, maybe you can wait until some lions take it down for you, then scare them off with fire and spears or take the risk and fight them, or take the risk and fight the mammoth yourself.
(Mammoth, Cave Bear, Bear = 2-3 lionesses). That way you can still hunt lions, jaguars, dholes, wolves, and leopards in their respective groups without worrying about other packs swooping in to make things difficult.
That's just my opinion, but I honestly do enjoy the idea. Su! Su!