Chances are the hyper threading helps, it does help in some games. As also evidenced by the benchmarks, clock speed also matters. That's also true of bf1, another multiplayer online game. If taking techspot's results yes the i7 got higher fps. People automatically say 'oh, hyper threading'. If looking at one i7 to another with a 1ghz clock speed difference came a 40fps difference as well. Hyper threading doesn't explain that since all the i7's are hyper threaded.
It's also difficult to get solid benchmark results for a game that's solely online multiplayer. People will say that predetermined scenarios like a built in 'benchmark' included in some games is unrealistic. It is, but it's also repeatable which is what benchmarks rely on to be able to consistently duplicate results.
The less variation the more accurate a benchmark by nature. That's why they don't compare a hyper 212 evo with ambient temps of 30c to a noctua nh-d14 at 22c ambient room temps to a cryorig h5 at 18c ambient room temps and each of the tests using different stress tests. One using p95, another ibt and another aida64. All that will be learned from that is different components operate differently under different conditions. Techspot's cpu performance was an entire article, not just one page and they mentioned how difficult it is to perfectly duplicate an mmo game. 3 different people could all play against xyz opponents all with the same exact pc and all get different results so which one is accurate? They all are.
Since there's no way to 'officially' benchmark a game that can only offer 'random' gameplay it's fair to look at what individual users are experiencing. Two users, one with a 4670k and a gtx 970 getting 120-160fps and another with a 4690k and gtx 970 with 90-100fps on ultra. Both oc'd, similar hardware, two different game experiences.
https://www.reddit.com/r/pcgaming/comments/4l9u2i/overwatch_benchmark_almost_40_gpus_tested_by/?limit=500#bottom-comments
If looking to do this 'professionally' then there's no reason not to be using the 6700k oc'd for the best performance.