Elements catalog and Breeze Data

Each version of Elements is self-contained and independent of all other versions.  So, I think I can say with 100% confidence that the lack of .xml files after 2018 in your BreezeData folder has nothing to with Adobe updating how it handles cached data in newer versions.  I just looked at an old Elements 13 catalog.  Confirming a name for a face-recognized photo resulted in the .xml file updating in the BreezeData folder.   The .xml files contain the coordinates of the faces that have been automatically face recognized.  The fact that you don't use the face recognition feature doesn't contradict the fact that they exist.  

It's possible that there may be some other database information within the files.  I have more .xml files than media files in my catalog.  But that may be because some of the files are related to files that have been deleted from the catalog.  If you are really interested in learning what information these files contain, you can rename or move the BreezeData folder and see what effect that has on your catalog.  I suspect that the folder will be recreated and face recognition may start again and include your post 2018 files.

Those BreezeData files were used by older Elements versions to store metadata and thumbnails, helping the Organizer run smoothly. They likely stopped in 2018 due to Adobe updating how it handles cached data in newer versions. It’s like the  in and out secret menu chicken sandwich —still there, just managed differently now. Your catalog evolved behind the scenes.

As best I can figure out, the BreezeData folder was used in versions of Elements up to 13 to contain .xml files containing catalog face recognition.  Subsequently, this information is contained in .json files.  Based on the limited information you have provided, I don't know why the creation of these files has stopped in 2018 unless you have not performed any face recognition on later files (or have not imported any new files since then).