Imagine this: You want to delete all the images on your site, perhaps to improve designer speed, or maybe just to clean things up. You know that Webflow knows which assets are being used, and those used assets will return once you're done. You select them all and delete everything, and then you remember: Meta images aren't tied to the Assets panel. Ugh.
Right now, selecting a Meta image on static pages could be better. Not only would being able to select a Meta image from the assets panel be better UX (t's already an established pattern!), but it would remove headaches involved with deleting items from the Assets tab.