I am still really enjoying my PRS-29A, but since getting my Smiths W10 it doesn't get quite so much wrist time

I have noticed that typically the PRS-29A (including the re-stocked current version) has the 2801 movement, so when I noticed my 2013 watch says it has a 2804 on the case back, I presume it is in the minority and has had the date mechanism removed? Was it only the 2013 run that had this movement? Be interested to understand if anyone has more info on when this movement was swapped in/out.

Thanks.