As T127509: Uninstall the Gather extension from en.wikipedia.org was fixed, Gather is now abandoned and practically unused. To reduce maintenance costs and attack surface, as well as for transparency, it should be undeployed as soon as possible. It's pretty easy:
'wmgUseGather' => array( 'default' => false, 'testwiki' => true, 'test2wiki' => true, 'enwikivoyage' => true, // T97488 'hewiki' => true, // T97488 ),
there are only a dozen users in 2016.
Also, per T97488: Enable Gather on English Wikivoyage and Hebrew Wikipedia, the installation was not asked by those wikis. So it's enough to notify the Gather users.