Warning: Contains SPOILERS for A Quiet Place Part II.
The opening scene of A Quiet Place Part II reveals more of the monsters' origins and how they came to Earth, but it seemingly retcons some details established in 2018's A Quiet Place. John Krasinski's debut movie as a director became an unlikely franchise starter, with its ending very much setting up more adventures to come as Evelyn Abbott (Emily Blunt) and her kids attempted to take the fight to the monsters. This continues in A Quiet Place 2, which makes some more reveals about the creatures.
Some of these build on what was setup in A Quiet Place. For instance, A Quiet Place 2 reveals water as the monsters' key weakness, something that Krasinski's Lee used in the first movie, while it takes the radio feedback tool and, by the end, uses it on a much bigger scale. But for all the monsters are present throughout A Quiet Place 2, the biggest use of them comes in the opening, which shows a very different side to the franchise.
A Quiet Place 2's opening scene essentially flips the premise: beginning at a baseball game and then showing the monsters arriving on Earth, it's a sequence full of noise. It shows a brief slice of normal life, and then the reactions people would obviously have to giant aliens coming to kill them, full of screeching cars and screaming people. It's thrilling and chaotic in equal measure, but it also doesn't quite fit with what was previously shown about the monsters. In A Quiet Place, Lee has a newspaper clipping that details a meteor landing in Mexico, which was the biggest hint at their origins, and ostensibly ground zero. Given A Quiet Place 2's opening takes place in New England and shows the meteor, though, then there's no way it's the same one, because it wouldn't be visible.
This itself doesn't completely break A Quiet Place: while there's no mention of other meteors, it doesn't completely mean there weren't any. Lee's board also contains some different time notes - referencing Bogota, Moscow, and Boston - which seemingly indicate different landing sites and times. Still, it does raise further questions about how these events happened and the spread of information. With several different landing sites around the globe, and the US military seemingly overwhelmed reasonably quickly (itself referenced in a news report), then just how was news of Mexico's meteor printed in a newspaper? As A Quiet Place 2's opening shows, the monsters destroyed places and people fairly quickly, and while there was surely some resistance, it's makes it harder to fathom how those pieces fit together.
Further complicating matters is the size of the meteor in A Quiet Place 2's opening. Given the visibility of it, then it's obviously enormous (which makes sense, since it's carrying a horde of monsters). But a meteor of that size would cause an incredible amount of damage itself, even before the aliens on it are unleashed. There's no real sign of that happening in A Quiet Place Part II, because the focus is very much on the monsters, which confuses things more. The clipping about Mexico compared it to a nuclear blast, so why doesn't that happen here? Since the monsters took over the New England town so quickly, and other events were apparently already happening concurrently - such as in Shanghai - then the timeline of events in A Quiet Place and the alien takeover feels rather murky at best. It by no means ruins the movie, with the scene itself exciting and what follows just as good, but the answers just raise more questions about how everything happened.