Is this a thing that we're ever actually going to see?

We were originally told the Burning Shrine was exclusive to the Trials only for that to not be the case. It seemed like the top tier pvp event, but Iron Banner is now getting buffed gear in-line with raid gear.

Haven't heard anything about it since launch.

As far as I could ever tell nobody ever said that Burning Shire would be exclusive. As for the Trials... maybe the improvements to Iron Banner will help make the experience better?

The article in that link is really depressing though.

Jonty Barnes: Yeah. You haven’t experienced all of earth. If you’re a higher-powered Guardian you’ll be doing additional experiences on there that are harder that open up combatant behaviours that aren’t available at the lower levels.

Well, no, that's blatantly wrong. You experience all of Earth before level 10 and adding additional enemy spawns or turning on the Lightswitch modifier doesn't change that. Expansion content might populate all those locked areas on Earth, but that's sure not the base game.