Coach resumed adding the stamped serial numbers on most bags in 2017.
I believe there also were a few styles between 2014 and 2017 that still had some kind of serial number, possibly some 1941 styles? Some of them had non-standard (basically made-up) serial prefixes. I stick with mostly vintage bags so I'm not sure.
ETA-
The 2014-2017 serial number debacle has been discussed often, and I included a summary of the mess in the Salearea Guides posted in the Coach Shopping forum in 2018, see Post Number 15. I strongly suggest that Coach buyers and collectors read the entire thread and Bookmark it. The thread also includes the Daria48 Fake Coach Numbers List:
Now that ebay is removing the guides they've been hosting for years, those who use those guides have been forced to either save them on their computers or print them. Tonight I found that the Salearea guides (including the Hyacinth/Salearea collaboration ones) have been saved to Salearea's...
forum.purseblog.com
But whether it has a fully stamped creed or one of those almost impossible to find small white fabric tags near the bottom of the inside pocket, those bags should still be authenticated here before buying.