With Amy Hennig taking her talents to Naughty Dog and Legacy of Kain: Defiance not selling as well as expected in 2003 despite favorable reviews from critics and audiences, the developers, Crystal Dynamics, ended up putting the Legacy of Kain series on ice. But, in the years since, Crystal Dynamics and their former owners, Square Enix, have shown interest. For example, there was the unreleased multiplayer game, Nosgoth.
Having said that, now that Crystal Dynamics has regained ownership of Legacy of Kain and other IPs like Tomb Raider, it appears that they're ready to revisit the iconic franchise.
As per Twisted Voxel, Crystal Dynamics sent out feelers in the form of surveys that asked the users if they were interested in a remake, reboot, or sequel to Legacy of Kain. In addition to this, the survey asked users about their interest in vampire video games as well as if they've had previous experience with the older Legacy of Kain titles.
The departure of Amy Hennig effectively ended the Legacy of Kain franchise. It wouldn't be far-fetched to say that Hennig is Legacy of Kain. She's even described the series as her "greatest achievement."