If you use oil filter brands other than AC/Delco this doesn't affect you, although I suspect similar shenanigans goes on with other brands as well.
Lately I've found that all the AC/Delco filters sold at Walmart have the letter "E" affixed to the normal part numbers (PF 47E, PF 52E, etc)...one look and I can tell you these are substandard filters, nowhere near the quality or design you expect in a Delco filter...lightweight cans, flat thin endcaps, no visible anti-drainback valves, etc....
Don't buy these things, is my advice. I have no empirical data to suggest they are not gonna perform to standards, but somebody's gotta be first, and it ain't gonna be me
I suspect the "E" stands for "economy", and is possibly one of those concessions manufacturers have to make in order to continue hitting Walmart's unrealistic price points. Don't be part of the experiment.