Satin finishes on Jefferson "Return to Monticello" Nickels

So, I was just happily roll searching nickels to pass some time, when I noticed something unusual.  I was comparing my finds against specimens already in my collection, to check for upgrades to grade and/or eye appeal, when I found a drastic difference in appearances of some coins of apparently the same type + year + mintmark, but without any indication that the difference was related to wear or circulation.  Instead, the difference appeared to be an intentional design change or different finish applied during minting.  So I checked the catalogue and found that for these "Return to Monticello", there are 5 years that have a variety(not sure if that's the correct term here) of “Satin Finish” listed for some years in the catalogue:  

Having apparently resolved the mystery, I continued with my searching … until … I found what appears to be a “Satin Finish”, but for a year/mintmark combination that the catalogue doesn't have any “Satin Finish” listing.  I attempted some online/armchair research (google, ai, PCGS site, and US Mint site) and found only indications that the coins I was finding shouldn't exist.  Or, at least, I found NO indication that they SHOULD exist, and yet they do.  

All indications I was able to find indicate that these Satin Finish nickels should have ended in 2011, at the very latest.  But I have examples from 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2021, 2022, and 2023 from both Philadelphia and Denver mints, and one from 2020 from Philadelphia and one from 2025 from Denver.  

At the time I came across those, I had no NON-Satin Finish examples from those years, so I assumed they were simply the normal finish.  However, I have now started coming across examples of the more standard gloss finish for those years and mint marks.  And to get ahead of the guess that maybe these more glossy examples are proofs, none of them are from San Francisco mint, where all the proof varieties should apparently be from, according to all documentation I could find. 

Does anyone know what's going on with these?  I'm finding 2 different finishes for years/mint marks where I can only find indications and documentation saying that only 1 finish should exist … What am I missing?

I think what you're seeing is the difference in luster caused by die usage. New, freshly engraved dies provide a reflective, sometimes proof-like finish but as they age and become worn it gradually changes to a frosted, satin-like one with more noticeable cartwheeling.

I hadn't considered that.  While I admit it's a possibility, I'm struggling to accept it as the correct explanation, simply due to how drastic of a difference I'm seeing.  Especially since I've never encountered a similar difference in any other coin type I've dealt with.