I'll give you that, it is an assumption... although I wouldn't call it an assumption as much as a hope, or faith in humanity, lol. It would be, uh, hard (to say the least) for the GA not to see that as a rip off. 14 years isn't 40 years. The effects hold up, and the scene was pretty dark in its own right, man, it had a teenage girl screaming for her life and being held by the friggin throat over a bridge. Come on.
Also, the Norman/Gwen thing: if the movie ended in that note of tragedy and soul-consuming revenge, that would make TASM 3 an ABSOLUTE must see, for reasons other than just "Hey, a new villain!" (Or even "Hey, six villains") It would be two years of giddy nail biting and foaming at the mouth just to see the badass moment when Peter finally came face to face with his gf's killer. But of course, that's just my take on it.