Marvel Cinematic Universe is leaving the Infinity Stones, the Infinity Gauntlet, and Thanos behind, but the consequences of their actions can still be felt in Phase 4. The MCU is now focusing on new characters, events, and concepts, mostly the multiverse, but it took a break from the multiversal chaos to introduce the Eternals.
Directed by Chloé Zhao, Eternals introduced the title team, an alien race created by the Celestial Arishem the Judge, who sent them to Earth centuries ago to protect it from the Deviants, their evil counterparts. The Eternals stayed on Earth to help humanity evolve but without interfering in their conflicts, and this eventually created tension between them, leading them to part ways. The team reunited many years later to stop the Deviants one more time as well as The Emergence, an event that would have led to the total destruction of Earth. What led the Eternals to this was learning the truth about their origin and mission, as they had been living in a lie for centuries.
Through their Avengers: Infinity War delayed the Emergence a couple of years – however, the snaps in Avengers: Endgame (the one by the Hulk and the one by Iron Man) might have gotten it back on track or even accelerated the process.
Tiamut’s emergence, thus accelerating the process and with that the plot of Eternals.
The consequences of the events of Avengers: Infinity War and Avengers: Endgame will continue to be felt in the MCU and will gradually decrease, so it’s unknown if a potential sequel to Eternals could address whether those events contributed somehow to accelerating the Emergence or had no impact in it – but it would be interesting and ironic if Thanos’ snap delayed the emergence of Tiamut and the final two snaps made up for all that lost time.