After the events of Avengers: Infinity War (and then once more after Avengers: Endgame), a lot of people became very interested in Thanos, and very quickly. Even as far back as Spider-Man: Far From Home, there were references to those battles in airplane movie catalogs or books.
However, these glimpses at what the general public of the MCU knows are vague and fleeting. Is it public knowledge within the MCU that the Avengers went back in time? Or do only the parties involved know exactly what happened?