Pure speculation, but it's possible you are both correct. They definitely scrape the link for a preview when you paste (or if someone's already shared it, maybe

Pure speculation, but it's possible you are both correct. They definitely scrape the link for a preview when you paste (or if someone's already shared it, maybe just re-use the info from a previous scrape) but probably it's not stored in their database (and thus available through the Graph API) until after it's been shared. (Or clicked on?)