That bothered me for a moment, but then again fighting Thanos was likely the most important battle in cosmic history, and it happened on earth. I recall the details we have on say Napoleon wars and troop movements, so it would make sense Shield and other intelligence agencies would have all the information and briefings from Iron Man, Captain America...ect to what happened exactly.
There were likely books written about it and websites dedicated to every detail.
Yeah I took it as that. I generally dislike it when characters narrate a story they are not a part like they were with the audience witnessing it, but in this case, I gave it a pass because of what you said above.