So it turns out that a new Unreal Tournament game isn't underway, but Epic Games is working on a "competitive online action game". Thanks to Selerox, Blue's and CVG for pointing out this job posting:
Epic Games is looking for a Systems Designers to join one of two projects. One of the teams is working on an unannounced competitive online action game that includes player progression, heavy itemization, and a dynamic economy; the other is for Fortnite. In either of these roles you'll be working on the biggest most important systems and will have a hand in designing everything from economics and itemization to balancing combat mechanics. You'll be responsible for general design, balance, rules, interface, etc. and will play an integral role in defining the outcome of the project.