ISTWCMS-4874: refactor exemptions, fix comment

uw_fdsu_theme_resp.theme

@@ -99,7 +99,7 @@ function uw_fdsu_theme_resp_preprocess_region(&$variables) {
   }
 
   // ISTWCMS-4847.
-  // If we are on the main content section, the check if 404 and add
+  // If we are on the main content section, the check if not a node and add
   // appropriate classes to display proper width.
   if ($region == 'content') {
 
@@ -109,11 +109,12 @@ function uw_fdsu_theme_resp_preprocess_region(&$variables) {
     // If we are on not on a node, add appropriate classes to show
     // proper width.
     $route_name = $route_match->getRouteName();
-    if (!in_array($route_name, [
+    $exemptions = [
       'entity.node.canonical',
       'entity.node.latest_version',
       'layout_builder.overrides.node.view',
-    ])) {
+    ];
+    if (!in_array($route_name, $exemptions)) {
       $variables['classes'][] = 'layout';
       $variables['classes'][] = 'uw-contained-width';
     }