Yes, I am am really eager to see how this turns out given the talent behind the production.

I might be more eager to see how this ties into the mechanics of AAA games and storytelling. Several people on this forum have said they never were able to get into Last of Us because they just didn't find it fun. So would a TV series allow them to enjoy the story? Or would it lose what made it special because you are throwing away the "moments a film editor would cut out"?

I think there is a unique strength to the show that games rarely ever get right, and that's flashbacks and character perspective.
Flashbacks in games are almost always jarring, especially when they present you with a different set of game mechanics that affect how you play. Left Behind did this too, and while it was great as its own thing, nobody who has played through it ever brings up the half of it where you play through the Winter section, despite it being the most traditional gameplay-heavy portion, and that's because it doesn't really have much to do with the flashback (other than the loose setting), or matter to the story being told at the present time. So while the Flashback bits are great, the interrupts from/to the present-day cause a bit of frustration with each jump.
Part II avoided this pitfall by letting its flashbacks serve as either transitions after complete scenes (Abby's hospital dreams being thematically tied to her actions after each day.), or as complete standalone segments that don't get interrupted (Joel and Ellie's birthday trip, Abby and Owen's date at the Marina).

A show can transition to flashbacks pretty freely, and the writers have a solid opportunity to blend Left Behind into the story in a much more organic manner, which is where character perspectives come in.
Games by design lock you into a narrow perspective (games that divert from this usually have the ability to play as multiple characters as the while "gimmick" of the game itself, and rarely is it in a narrative sense*), you are kind of "in the shoes" of a single person, rarely as more than one at a time. With a show, we can get to know characters like Tess, Marlene, Tommy + Maria, and even David. We're already going to get moments between Bill and Frank, which the game had none of (Bill will reportedly be in nine out of the ten episodes, but no telling if this was an accurate report), and I'm eager to see how they can make us care more about the ancillary characters, since outside of the segments with Sam and Henry, TLoU was a fairly lonely affair throughout.

What are they adding to compensate?

Flashbacks! Extended moments with characters we might not have cared much for otherwise! They do have ten episodes to cover, and Craig Mazin did an amazing job at handling an ensemble cast across five episodes with Chernobyl, so I'm pretty eager to see the world outside of the relationship between Joel and Ellie (which is what I wanted in the first place).

Will AAA games start shifting to mechanics of exploration and discovery rather than those of challenge and conflict? Would such games become the best way to tell stories in the future?

Nah, and probably not.
Well, The Last of Us was a narrative-focused game. It didn't need "Challenge and conflict" outside of what pushed the story forward. You could cut out 2/3 combat encounters, and the core of the game would remain intact.
Also, a brilliant narrative game built almost entirely around challenge and conflict is "Thomas Was Alone", which starts as a simple narrated puzzle game, but eventually becomes a game where solving the puzzles becomes defiance, courage, rebellion, and sacrifice. So yeah, I think the potential of games isn't something we should be worried about with regards to shifts.

It's cool to be on the bleeding edge of a very interesting time for storytelling moving into the future.

Heck yeah, remember that for ages, book series' felt impossible to adapt to a visual medium, and yet, the first four and a half seasons of Game of Thrones showed us a magical world of what could be, and I hear great things about the Villeneuve Dune. We'll see!

*Clive Barker's Jericho is one of the few examples to integrate the "play as multiple characters while maintaining a focused perspective" mechanic, as you are playing the literal spirit of the squad's leader possessing different members of the group throughout the narrative. Underrated game!

Yeah, that looks fantastic. Let’s hope it turns out well. The Halo show demonstrated the strengths of creating a new story disconnected from the source games, so let’s hope the Last of Us show can do as well with a direct translation.

I wonder too.

There's going to be 10 episodes, and the game has about 2 hours of cutscenes. That's 6-7 hours left to fill with stuff that happens in game while you have control. I don't see how it can be a straight adaptation without adding tons of stuff.