No I think that you're right, it's not possible to subscribe to tags. But you can help upvote the proposal on @utopian-io (if it's the same as what you were thinking of)
https://utopian.io/utopian-io/@michellerhey/suggestion-add-more-links-or-your-own-links-to-links-section
RE: No easy way to subscribe to a tag(s)