Confirmed.

It has nothing to do with Sample Data but with the sql statement for selecting featured articles with ordering.

Not only featured articles.
If you create a category blog and set ordering to modified, the same error occurs with a slightly different stack trace:

[12-Dec-2020 23:32:50 Europe/Oslo] PHP Warning: Invalid argument supplied for foreach() in D:\virtualhosts\new40\components\com_content\src\Model\ArticlesModel.php on line 713
[12-Dec-2020 23:32:50 Europe/Oslo] PHP Stack trace:
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 1. {main}() D:\virtualhosts\new40\index.php:0
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 2. require_once() D:\virtualhosts\new40\index.php:36
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 3. Joomla\CMS\Application\SiteApplication->execute() D:\virtualhosts\new40\includes\app.php:63
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 4. Joomla\CMS\Application\SiteApplication->doExecute() D:\virtualhosts\new40\libraries\src\Application\CMSApplication.php:233
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 5. Joomla\CMS\Application\SiteApplication->dispatch($component = uninitialized) D:\virtualhosts\new40\libraries\src\Application\SiteApplication.php:245
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 6. Joomla\CMS\Component\ComponentHelper::renderComponent($option = 'com_content', $params = uninitialized) D:\virtualhosts\new40\libraries\src\Application\SiteApplication.php:206
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 7. Joomla\Component\Content\Site\Dispatcher\Dispatcher->dispatch() D:\virtualhosts\new40\libraries\src\Component\ComponentHelper.php:389
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 8. Joomla\Component\Content\Site\Dispatcher\Dispatcher->dispatch() D:\virtualhosts\new40\components\com_content\src\Dispatcher\Dispatcher.php:55
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 9. Joomla\Component\Content\Site\Controller\DisplayController->execute($task = 'display') D:\virtualhosts\new40\libraries\src\Dispatcher\ComponentDispatcher.php:146
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 10. Joomla\Component\Content\Site\Controller\DisplayController->display($cachable = uninitialized, $urlparams = uninitialized) D:\virtualhosts\new40\libraries\src\MVC\Controller\BaseController.php:729
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 11. Joomla\Component\Content\Site\Controller\DisplayController->display($cachable = TRUE, $urlparams = ['catid' => 'INT', 'id' => 'INT', 'cid' => 'ARRAY', 'year' => 'INT', 'month' => 'INT', 'limit' => 'UINT', 'limitstart' => 'UINT', 'showall' => 'INT', 'return' => 'BASE64', 'filter' => 'STRING', 'filter_order' => 'CMD', 'filter_order_Dir' => 'CMD', 'filter-search' => 'STRING', 'print' => 'BOOLEAN', 'lang' => 'CMD', 'Itemid' => 'INT']) D:\virtualhosts\new40\components\com_content\src\Controller\DisplayController.php:125
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 12. Joomla\Component\Content\Site\View\Category\HtmlView->display($tpl = uninitialized) D:\virtualhosts\new40\libraries\src\MVC\Controller\BaseController.php:691
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 13. Joomla\Component\Content\Site\View\Category\HtmlView->commonCategoryDisplay() D:\virtualhosts\new40\components\com_content\src\View\Category\HtmlView.php:73
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 14. Joomla\Component\Content\Site\View\Category\HtmlView->get($property = 'Items', $default = uninitialized) D:\virtualhosts\new40\libraries\src\MVC\View\CategoryView.php:158
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 15. Joomla\Component\Content\Site\Model\CategoryModel->getItems() D:\virtualhosts\new40\libraries\src\MVC\View\AbstractView.php:146
[12-Dec-2020 23:32:50 Europe/Oslo] PHP 16. Joomla\Component\Content\Site\Model\ArticlesModel->getItems() D:\virtualhosts\new40\components\com_content\src\Model\CategoryModel.php:284

Closing as there is a PR. Please test #31645