It appears Google isn't done making Gmail a lot more useful. Available with the latest update version 8.5.20, it is now uncertain whether the feature has been available since the latest version's release date or is a server-side update. Now you're in charge of what happens when you swipe on an email. Until now, it was impossible to designate a certain functionality to swipe gestures - doing so only archived an email.
The change appears to be slowly rolling out, but Google is finally going to let you customize the swipe actions within Gmail on Android. The options for swiping now include: Archive, Delete, Mark as read/unread, Move to, Snooze, and None - and obviously you can customise both left and right. Google is not the first one too offers its email platforms users with such options, there are plenty of other platforms which are already serving this feature. Setting it to "none" is also possible for those who don't want to bother with gestures at all. Once configured, it should work across the entirety of the Gmail app.