I guess it depends where the press release is targeted for but it's a global industry and a global audience now so surely it's not that hard for them to say "June 2017"
I also hate 'Coming Fall 2017...' particularly for movie trailers. Not only do you have to translate to Autumn, you also have to Geo-localize it. So for me that means Spring.
First world problems
back on topic - I think it's a good thing for MS to be clear about capability and the market position as far as Scorpio goes. Sony are marketing the PS4 Pro as 4K gaming but I doubt anyone would legitimately get 4K + decent Frame rates in any title. That won't stop the masses from stating it as fact, regardless of what resolution it's actually outputting.