Q:
Will Queen's Gauntlet be removed on the 20th?
Known Content Deadlines:
Ending on August 20th
Opening Ceremony instance
Ending on September 3rd
Queen’s Jubilee and The Queen’s Speech story content
Queen’s Gauntlet
Crown Pavilion area
Hot air balloons
Beacons of Kryta
Living World achievement categories, and the special Daily achievements for Queen’s Jubilee
https://forum-en.gw2archive.eu/forum/livingworld/jubilee/Queen-s-Jubilee-release-page-GW2-Wiki
Here’s official confirmation that people have another 2 weeks to complete all of the gauntlet achievements:
Yes, you will be able to play the Queen’s Gauntlet after August 20th.
https://forum-en.gw2archive.eu/forum/livingworld/speech/Gauntlet-in-Queen-s-Speech/first#post2619092
Anthony did also confirm that the Queen’s Gauntlet will be returning in the future, much like the Super Adventure Box, and that he’s “very, very sure” that the achievements would still be completable when it does. (However, he didn’t say whether the rewards like the Liadri mini would be, which is a bit concerning for those who are ardent mini collectors.)