Originally Posted by Spider-Fan
They've said it doesn't ignore X3, and it has most of the original cast back. I think that makes it X4. Some FC characters are in it, but that doesn't make it FC2. That just means they're including prequel characters.
Actually when it was first announced Singer said it was the sequel to First Class. He said it's going to fix some of the continuity issues between the two but that's not the main focus of the film. He then went on in another interview to say it's both a sequel to First Class and the original trilogy. Does that make it X4, no it doesn't. They can't go X-Men 3>>X-Men: First Class>>X-Men: Days of Future Past then X-Men: First Class 3 and X-Men 5 it doesn't make sense.