I kind of get what he's saying here. When I saw the new TCM, aside from the addition of way too many family members, I got more of a feeling that it was just another story related to the "mythology" and not necessarily a remake. That's probably what this film will be. He says that Jason will be wearing the hockey mask, so it's definitely taking place after the events of Part 3, and since he gets "laid to rest" in Part 4 for several years (until Part 6) than I am guessing that it'll be taking place before the events of Part 4. So, a Part 3.5 I guess. That is, if they're going for any kind of continuity with the original series, which I hope to fuck that they do.
Not really any time for something to take place between 3 and 4, part four began right where part 3 left off, he got carted off to the morgue, killed a couple people there, then went back to the camp....so unless part 3.5 is his walk back to the camp, I don't think there's much there.