Firstly, I'm not joking. There will be spoilers for the end of Watchmen here, and if you don't want to know, turn back now. I've been very unspoily elsewhere, but this one is unavoidably filled with spoilers for the end of the story of both the comic and the movie. This is your last warning.
Still here? Okay.
As anyone who's paid attention to our coverage of Watchmen undoubtedly knows by now, the end of the Watchmen movie does not include the giant alien squid destroying Manhattan that the book climaxes with. Admittedly, when you put it like that - "the giant alien squid destroying Manhattan" - it sounds ridiculous, like a bad monster movie or something, but that's kind of the point, both inside and outside of the story.
It's the ridiculous, surreality of an alien squid that is required to shock the various superpowers out of their Cold War mindset in Ozymandias' plan; something so literally beyond the realms of possibility that its very appearance makes everything else seem equally absurd and forces political powers to reassess their priorities and put aside prejudices to deal with this new perceived threat. The squid doesn't just provide the climax to the story, it also provides the start; it was the Comedian seeing experiments that led to the squid's creation that led to his murder.
From a meta context, the squid provides a reference to the monster comics that pre-dated the Silver Age where superhero comics became the dominant force in the marketplace (What better to provide an end to superheroics in the Watchmen world? The narrative almost reads as a backwards comment on the maturation of the medium, opening with a brutal, realistic murder and then ending with a cartoonish monster apocalypse) while also exploding both the world that Moore and Gibbons had created and the rules that they had imposed on it with something so unrealistic - and, yes, unfilmable - that it could only work in comics, where imagination and conviction are all that's needed to make an idea work. By bringing in the idea of an alien giant squid - Interestingly enough, just like Starro The Conqueror, the first villain fought by the Justice League of America, DC Comics' premiere superhero team and the direct inspiration behind the creation of the Fantastic Four, which in turn led to the creation of Marvel Comics as we know it today - to a story that, Dr. Manhattan aside, had remained mostly grounded, the possibility and idea-driven nature of comics is restated, as is (in a strange way) the need for superheroes to battle such outlandish threats. The story comes full-circle, and the critique of superheroes closes with a return to imagination and the impossible, albeit one done in a downbeat tone consistent with the rest of the book.
Meredith is right; the loss of the squid, and the destruction that it brought with it, is a loss to the movie. Perhaps what replaces it fills a plot hole, but it's unlikely that it will hold as much meaning as what was removed.