When logging in with PluggableAuth, the "remember me" flag (aka "Keep me logged in" checkbox) is not set. In most cases it would make sense to set it - it makes logins last longer by detaching them from the session handling of the wiki (and also using a longer cookie lifetime).
|mediawiki/core||master||+163 -11||Make RememberMe authentication behavior configurable.|
With respect to the patch, my thought is that environments (like NASA's) where the wiki is only accessible from their enterprise network, their wikis could be configured to ALWAYS_REMEMBER. The default is the current behavior, CHOOSE_REMEMBER, which still allows the login form to be bypassed. For environments where the wikis could be accessed from public networks, it could be set to NEVER_REMEBER, or, if you trust your users, FORCE_CHOOSE_REMEMBER, which would force showing the login form and would allow users to select Remember Me.