I don't think it's a great term though, first because it has been used in the past to describe dumb phone browsers with limited functionality but that still renders a page. The important distinction being that rendering happens.
Second, these are parsing metadata found in the page. It's actually much much closer to a bot than a browser and perhaps best described in those terms. It's a bot that only wants to figure out a preview for a target URL. Preview bot.
I'm curious if this worked because as far as I'm aware, most of these are basic HTTP requests where the meta tags are parsed without the JS being executed.