Widgets_init中的奇怪的WordPress错误在运行带参数的新WP_Query时进行过滤

Question

When using TwentySeventeen theme, if you have a function with a simple new WP_Query with any argument like this in the functions.php:

function wp123_qry_in_widgets_init() {
    $test_qry = new WP_Query( array( 'posts_per_page' => 3 ) );
    if ( $test_qry->have_posts() ) : 
        while ( $test_qry->have_posts() ) : 
            $test_qry->the_post();
        endwhile;
         wp_reset_postdata();
    endif;
}  

And then hook it on to the widgets_init action with:

add_action( 'widgets_init', 'wp123_qry_in_widgets_init' );

Something weird happens when you go to Media -> Add new. When you upload a new image now, the image goes into a seemingly random upload date folder.

For instance, I did it just now and new images are uploaded to 2016/11. Without that function added, the images are uploaded normally to 2017/01.

Why is this unexpected behavior happening?