They’re both products of their times. The squid made sense in a time where comic books weren’t as grounded as they are today.
Also a squid makes more sense when you actually foreshadow a squid. The movie would have had to shoehorn that in through the plot and that would have been a mess.
It was cleaner. Different medium, different capabilities.
I don’t see how foreshadowing improves anything. Ozy explaining his bizarre and horrible plan and then revealing it’s already happened is a wonderful moment. Knowing it’s going to happen before it does would ruin it.
Foreshadowing the squid is well done in the comics and does not change the reveal. You should read it if you haven’t.