The "new releases" feed shows the 15 latest releases. Last year on January 1, I remember that there were (I think) 17 or 18 new releases all at once, so some of them were never displayed in the feed at all.
I don't know how many releases you expect on PD day this time around, but if it's close to 15, then you might consider increasing the size of the "new releases" feed, or maybe adding a "keep for at least x days" threshold to make sure releases stick around long enough to be picked up by feed readers?
Thanks!
Evan.