As indicated by a recent regression testing, action=logout has been removed from current Wikia release of MediaWiki API. This will cause the following exception when calling WikiSite.LogoutAsync for all Wikia sites on FANDOM.
WikiClientLibrary.InvalidActionException : unknown_action:Unrecognized value for parameter 'action': logout
From the information gathered, there is no pure MW API approach to just logout a user, and some workaround is inevitable.
As indicated by a recent regression testing,
action=logouthas been removed from current Wikia release of MediaWiki API. This will cause the following exception when callingWikiSite.LogoutAsyncfor all Wikia sites on FANDOM.From the information gathered, there is no pure MW API approach to just logout a user, and some workaround is inevitable.
c.f. Server-side logout procedure: https://github.com/Wikia/app/blob/4988ecbd6938a90f6f66fbc33cf31d63e720adcc/includes/User.php#L3155 (Thanks to fngplg)