I actually prefer the stickers and I'm hoping I get some for my upcoming trip. It's a room only package with no tickets, but it IS a package as it was booked through a TA discount. Not sure if we get them for that type of booking or not.
I like the new white stickers that look good on car windows. Totaled my car in June and need to replace the stickers I had just applied from my May trip.
Oh, but from your question, I don't think that is why. I really don't see any rhyme or reason to why they sometimes send luggage tags and sometimes don't, but you can always ask for them at the front desk.