The only thing I see on that page is a newsletter signup which seems like a different bird entirely. Can you tell us what part of the page you are referencing?
Honestly, I’m not sure if there’s much value in a feature to subscribe to ANY content, but I guess I’m mostly saying that since I’ve never seen that feature before. That may be an edge case.
Subscribing to new blog posts specifically though seems like common functionality I would almost expect to be core.