For those of you questioning the Mar 2020 validity of your matched Diamond - if you'd qualified this year, isn't that just the norm? From what I recall, you should get Diamond for the rest of this calendar year + the next (2019), so the status expires in Mar 2020.
(The website's also been updated to reflect this date, so I'm pretty certain your matches will be valid till then.
https://statusmatch.hiltonhonors.com/ )