Yes, but even this feature would be more like a traditional browser: A service-neutral, "dumb" feature where the user is directly in control. Not in an abstract marketing sense but literally: A user subscribes to a page and will get all events from tha page in predicatable order.
The "news feed" as implemented by Facebook and envisaged by Pocket is something completely different. You "subscribe" to pages alright. But this is simply a hint that gets fed into a curation algorithm. What you then see is a selected subset of events from your subscribed pages, in addition to "related" content and content the algorithm things you might find interesting. The algorithm used is of course constantly being changed and optimized towards a metric you probably don't even know. In short, with that kind of system, the user is very much not in control.
> I came home and investigated – the option to "subscribe to page" when the page has an RSS feed is gone from Firefox, or at least I couldn't find it.
Apologies for being cynical, but I'm not surprised. I'll be bold and assume that you can make money with curated feeds (or letting other people try out their curation algorithms on your userbase) but you can't make money with RSS.