Honestly, I think they are more likely to forget the chocolate than the Biscoff....on that note, the chocolate bar thing is a bit awkward in the sense that if you get a free drink, it's not very noticeable to those around you since drinks are available to everyone (just not necessarily for free). The chocolate, on the other hand, is not for sale and as folks are handed the chocolate, it's important for the FAs to make some verbal mention of status and/or thank the passenger for their business, otherwise it looks like someone got skipped over for a snack (like you did with the Biscoffs in this case).