What's the definition of 'iconic' we're using here?
To me, based on the original list, I'd say that means holes that are a big influence on architecture - i.e. imitations / homages to the Redan or Road Hole found at any places, or simply the architecturally knowledgeable seeing the parallels. On that basis, most of the holes listed after don't belong. Even holes that are maybe 'iconic' using the definition of "a hole that once you see it you will always remember it", because I've played most of them but only can come up with a mental picture for half of them.
Consider the difference between Lahinch's Klondkye and Dell. Both are something you will always remember, but the Klondkye is not something anyone is likely to deliberately build - even if Doak found a routing with a natural 50 foot hill in the middle of his prospective fairway I doubt he'd build that hole (but maybe I'm wrong, and he'd do it if the owner let him do whatever he wanted, if he reads this I'd be curious to know) The Dell, on the other hand, is imitated, knowingly or not, the world over. Heck a NLE nine holer I learned to play on my first summer had a sorta Dell hole (about 140 yards, slightly uphill, half blind sunken green with mounds around it) Whoever designed that hole had probably never even heard of Lahinch, but it stood out in my mind as a Dell hole afterwards. While a hole like Old Head's 4th is certainly memorable, it is to imagine ever seeing another hole that reminds me of it because the setting is so unique it cannot be replicated elsewhere.