The buyer may not have had a card to notify them, and may have been waiting patiently.

you never know. I rarely receive a card.

good idea to email them and follow it up 🙂

very few sellers I have dealt with would do that...out of sight out of mind. I know it is also the buyer's responsibility to check tracking if something appears awry...IF they have the number, a few sellers still do not see it is important to upload it, but it can be helpful to have.