Warning: contains spoilers for Fantastic Four #43!
The Fantastic Four's latest adventure had retconned an entire comic thanks to one single image, and an important lesson disappears from existence. The team is known for traveling through space, time and different dimensions, thanks to Reed Richards and his genius-level abilities. But even Mister Fantastic can't stop the Watcher's latest adventure from being erased, as Fantastic Four #43 shows during the cataclysmic Reckoning War.
The retcon concerns Uatu the Watcher's first instance of interfering with Earth during the famous Galactus Trilogy. When the Devourer of Worlds arrived to the birthplace of humanity, the Watcher decided to break his oath and aid the Fantastic Four, in particular sending the Human Torch on a journey to Galactus' ship. There, he obtained the Ultimate Nullifier, the one weapon that Galactus truly feared. The Watcher had saved the Earth from Galactus at the cost of his own oath - but would it have survived without his interference?
In Reckoning War: Trial of the Watcher, Uatu is strapped to the Seat of All Knowledge for his many crimes, and is forced to witness an alternate reality in which he did not interfere with Galactus' plans. Surprisingly, the Fantastic Four managed to defeat the being all on their own - and turn the world into a utopia with the technology they created. But in Fantastic Four #43, written by Dan Slott with art by Rachel Stott & Andrea Di Vitto, the Watcher sees the aftermath of the tale - in which Reed Richards' out-of-control 'zero energy' destroys New York, then the Earth...and finally the entire universe.
The Trial of the Watcher existed to prove a point: that there were consequences to Uatu's interference with humanity, even if said consequences wouldn't be seen until far into the future. But the above image completely retcons the lesson the Watcher would have learned about breaking his oath about meddling in the affairs of lesser beings. This comic proves Uatu was right the entire time and his interference and aid to the Fantastic Four saved the entire universe - he simply did not know it at the time.
Thus, the events of Trial of the Watcher serve no purpose other than to reaffirm what Uatu already believed: that his actions were completely justified. Retcons, or retroactive continuity, often eliminates entire events from the timeline, but in this case it eliminates a lesson to be learned. The Fantastic Four ultimately benefitted from Uatu's interference, but now there are effectively no consequences for a massively-powerful being like the Watcher to play God for as long as he sees fit.