We’re big fans of keeping Supernotes fast and minimalist with the pure Markdown format. However you’re right it’s quite useful to have a little preview of the link before you open it. Our current thinking is that this will auto render for links which are standalone on a new line; we could also add support for internal card links as well with little previews.
This is also related to Improving UX through Unfurling Links.
I’m marking this as under consideration for now, but if there’s enough interest we’ll bump up the priority (go like Jospeh’s post above if you’d want this) 