Potentially! In addition to the four issues of Heroes Reborn: The Return, there were seven HR one-shots in 2000 and two Onslaught miniseries, Onslaught Reborn and Onslaught Unleashed as well as the Exiles issues where they visit the HR universe.
I wouldn't be entirely surprised, though, if they just hold The Return for a post-HR Fantastic Four omni.