I wouldn't say ignore, it's more a best case scenario for GPUs that rely on boosting and can benefit from an open bench setup without a warm up.
Examples include: Fury Nano and every NV GPU since Kepler.
Also, TPU didn't use Doom Vulkan. They used Hitman DX11 and Rise of the Tomb Raider DX12. It's backwards actually when RotTR DX12 even in their previous testing, runs faster in DX11 for everybody. While Hitman DX12, AMD's lead grows.
At Computerbase, they included Doom w/ Vulkan and the result is well, close.
https://www.computerbase.de/2016-07/asus-radeon-rx-480-strix-test/2/#abschnitt_benchmarks_in_full_hd
One game can swing the results when the rest are pretty close. Examples: Anno swings wildy to NV, where a 970 is faster than Fury X. Likewise Project Cars. On AMD swing games, it's definitely Hitman DX12 and Doom w/ Vulkan.
So looking at it objectively, TPU's current testing, favors NV strongly while Computerbase's testing is neutral, because they include games that swing to NV and others that swing to AMD along with neutral titles.
Ultimately, these cards are very close, so you can skew it either way. If you did testing only DX12/Vulkan, you will swing it big time to the RX 480's favor. But that isn't an accurate picture of gaming, because DX11 games are still popular.