From FGN Online:
Having confirmed a Dreamcast version of Fighting Force 2 last week, Core has retracted the information.
"The Dreamcast version of Fighting Force 2 is no longer confirmed," said a spokesperson for the company. "The decision was taken by the directors in a recent meeting."
Very little is known on the sequel to Fighting Force, aside from the fact that a brand new engine has been constructed specifically for the title, it will be vastly larger than its predecessor and it's due out in October. Expect a more solid decision on the Dreamcast version at E3.
In further Core news, spreading rumors regarding a Game Boy port for Tomb Raider appear to be completely unfounded: "If it's true it's the first I've heard of it," the official source added.
Sounds to me like Core has a leak that they want to shut up real quick. These games are probably still coming to their respective systems, but they were announced a bit sooner than Core had wanted. We'll probably find out for sure after E3.