the YouTube description on the newly published teaser trailer (which you can watch below the break) says we can expect more details at the San Diego Comic Con, which takes place later this month.
Additionally, a quote from Game Director and Executive Producer Katsuhiro Harada points towards a release on the new generation of systems.
"The power and flexibility means that we can focus our efforts on making Tekken 7 the best possible game without worrying about spending time creating a stand-alone graphic engine," said Harada. "With Unreal Engine 4, we could rapidly achieve visual quality expected on next-gen platform[s] and go beyond it. Not only is Unreal Engine 4 powerful and easy to use, but it allows us to immediately bring Tekken 7 to any platform we desire."