Current datamined data shows engineering helms with no sockets. Fits inline with Blizzard's theme of reducing overall number of sockets on gear.
---
Don't be a victim of IFOWISNAWL!
Call 800-Calm-The-F-Down, Operators are standing by. Now taking calls on all your Legion worries.
Kind of. The cogwheels weren't really adding more stats to something like a traditional socket though, since eng helms had no secondaries at all. If we assume that raid drop helms have secondaries then I'd be surprised if the eng helms didn't end up with cogwheels. They aren't quite the same as traditional sockets, and Blizz seems fine with eng helms being pretty decent to start out with since they are never used again past the start of the first tier.