Change record status: 
Project: 
Introduced in branch: 
8.x
Description: 

The default value of the 'site_frontpage' system variable, which configures the site's front page path, was changed from 'node' to 'user', because Node module became optional.

Drupal 7:

<?php
$is_front_page
= ($_GET['q'] == variable_get('site_frontpage', 'node'));
?>

Drupal 8:

<?php
$is_front_page
= ($_GET['q'] == variable_get('site_frontpage', 'user'));
?>

If you want to restore the front page to 'node' in an installation profile, you may do so by:

  // Set front page to "node".
  Drupal::config('system.site')->set('page.front', 'node')->save();
Impacts: 
Site builders, administrators, editors
Module developers
Themers
Updates Done (doc team, etc.)
Online documentation: 
Not done
Theming guide: 
Not done
Module developer documentation: 
Not done
Examples project: 
Not done
Coder Review: 
Not done
Coder Upgrade: 
Not done
Other: 
Other updates done