There is absolutely nothing stunning or revolutionary about AC/DC. It's a pretty good pin, but I see nothing phenomenal about it's production, ranking or popularity on any site.
I don't agree with your list. It plain sucks. AC/DC premium LE is rated at 14 in the pinside ranking. There are 13 other machines ranked higher. And El Dorado? It's rated at 19 out of EMs on IPDB top 300 list and had a measely production number under 3000. It's ranked 18th on pinsides EM list. There's not a single 'historical' reason that should this pin should even be considered at all. I'm thinking of a lot more significant/popular EM games that could take the place of El Dorado.
however... I'll give you the Addams Family (significance: over 20K produced) even though I am not a big fan.
IMO that list should have these titles somewhere above the others you selected:
Medieval Madness - Over the top in my book, I don't really go for it but it's hype popularity and price put it in almost it's own class.
Attack from Mars - Popular A-lister and my personal fav.
High Speed - immensely popular during it's time and still sought after. Loaded with firsts:
First pinball to play a complete song.
First Williams pinball game to use alpha-numeric displays.
First use of Auto Percentaging (for replay scores).
First Jackpot available only during multiball.
First use of broken switch compensation programming.
First SS game with operator report.
Twilight Zone - "includes more features with patents pending than any other game in history!"