Just looking at Morgan Dollars, looks like NGC hasn't updated their coin values in 8 years or more? It isn't just low graded circulated coins, it's even more noticable in MS categories.
Honestly, I think all the price guides are very outdated right now. Inflation I'm sure plays a part in it but I think they're just out of date versus reality. Around 2014 I would have told you they're all high retail prices in the guides. Meaning higher than Street price for the most part. Now I think they're 10 or 20% lower than reality, at least as far as eBay prices, coin dealer prices, and great collections. This might be the first time in my lifetime that the price guide prices are actually lower. I can't think of another time or collectible where this would be the case, but I feel confident it's true for coins right now for NGC, PCGS, CACG graded coins with average to above average eye appeal.
I still see coins where the price guide is higher (noticed it yesterday when looking up several random examples on GC). I think the biggest contributor (at least on the lower dollar end) has been the rapid rise in gold and silver prices. For example, a few weeks ago we basically got to the point where all the common date Morgans had more melt value than guide up to MS 63. Also, post-2020 the coin market has had a strong run. We temporarily bottomed out in late 2019/early 2020 and that was probably the last time price guides were consistently high (I was tracking MS 65 Morgans and they got down to about $85 in greysheet and sales were concluding on GC in the $70-$95 range).
For the items based on melt prices, yes it should be easy. For items that use an average of sales, not necessarily as it still takes human intervention to toss out the wrong results (for example, PCGS coinfacts still links to sales of the wrong coin at times because the eBay description was incorrect...an example I've seen is where it pulls a gold coin instead of a silver for the silver guide).
AI would not be the final say, but it is extremely powerful at searching and presenting the results. It is a tool. Once the data is accumulated, it is fairly easy to group the accurate info and identify the anomalies. Those can then either be thrown out or investigated for accuracy.
I don't think you need AI to update those prices, I think just a very basic algorithm that takes into account current metal prices would be very easy, and I hope that the Prices guides already do this. (maybe they don't?) Of course, for branding purposes, its will be called "AI" even if it's just Billy in the backroom hand-updating each value. Thing is, the numismatic value shrinks on things whose prices primarily depend on the spot price of silver or gold. Meaning, a $2000 coin that has $1500 in melt value, and $500 in numismatic value, tends to not change price that much when the metal value shoots up, the numismatic premium tends to drop for awhile to eat up the increase in spot prices. At least that is my experience. The spot price increase would need to be greater than any numismatic value before the price really starts to move up on the item as a whole. Said another way, the spreads on premiums paid over spot shrink the higher the spot price goes, and this sort of makes the coin's price "sticky" around the historical price. If I am wrong about this, please correct me. In my opinion, coins that primarily are numismatic items are undervalued in the guides right now regardless of spot price. Maybe I only look at premium coins so my thinking is skewed here. But I only look at cheaper coins, <$1000 each, so its not like I am looking at high-roller items. Premium examples of cheaper coins are just way off in the price guides. It seems that most of us here are in agreement, so I tend to think it's actually a real thing. I wonder if one day soon we will wake up and the guide prices just suddenly jump 20%. If this is all driven by inflation, it's very unlikely that it will go back down. If its all driven by melt values, then yeah, it will go back down at some point. But I really think it's more than either of those two things. Maybe its all the flippers, or maybe its actually something good, like tons of new collectors are coming into the hobby. (I have no real evidence of this, except that coin shows near me seem to be quite healthy).
The trouble with lower grade materal, which has lost its numismatic value to its bullion value, is that the number changes daily, actually by the second. If you look at the Grey Sheet prices and see little or no difference between EF-40 and MS-62, you need to go the spot prices for gold and silver. They will tell you what that material is worth. As for the truly scarce and collectable material, the prices guides can't keep up with it. It's whatever the bidders in the big auctions take it. I bid more than the catalog and more than recent auction results on two 1793 Chain AMERI. cents recently. I came in third both times. I think some people don't have much respect for the U.S. dollar any longer.
For decades I have thought that the price guides did use AI - well, kinda. They used the "Artificial" part constantly - and never used the "Intelligence" part at all !
What you said is accurate. In terms of the increases, I believe it is a combination. Some of it is inflation, some is higher melt prices, some is more interest, and some is more money to spend (from those that sold their gold/silver at recent peaks or took profit on other things like bitcoin/stocks and are spending the gains).
The world coin pricing at NGC comes from Krause, I believe. If those listings for certain countries at Krause (numismaster.com) aren't updated, then they indeed look outdated.