I've done this twice, now. I went to File > Backup or Copy File > Create a Year-End Archive, set the "I only want transactions in my current data file starting with this date" to 01/01/2016, and told it to put it in an appropriately named file. After it finished processing, I told it to open the current file (not the archived one). The transactions in that file STILL run from 01/01/2015 (<-- 2015, not the 2016 date I set) to today. I've done this twice now. It's not removing the old transactions from the current file even though I told it to.
These are reconciled, standard, non-investment, non-transfer transactions (i.e., Cash, Checking and Savings). The same kinds of transactions I've been archiving out of my file for at least the last 25 years in an attempt to keep my file size at reasonable levels. Unless I've gone blind and senile enough to not be able to figure out what's staring me in the face, Quicken's Year-End Archive process no longer works.
Windows 10 Pro (fully updated, though not Windows 11), Quicken Premier v R47.15, build 27.1.47.15