I think you're reading into that article a tad too much. I can understand why AMD would be reluctant to give out specific gaming benchmarks on a card not designed for gaming.
You know how fickle people can be. AMD releasing gaming benchmarks for their Prosumer card would do them nothing but harm. Lets suppose that they did release benchmarks for it, and lets suppose that those benchmarks were identical to the Titan Xp (stress on the if, it wouldn't be) then what far too many people would take out of it is "Vega costs $1499 and performs worse than a 1080Ti". Or, people would say "Vega costs more than a Titan Xp for the same performance", and ignore that it beats it in areas its actually designed for, which isn't gaming. Basically, they can't win. Better to just hold off completely until the consumer version drops, then release benchmarks for that.