Just use !isHeritageClause(node.parent).

Author: DanielRosenwasser

src/compiler/utilities.ts

@@ -2017,7 +2017,7 @@ namespace ts {
             case SyntaxKind.MetaProperty:
                 return true;
             case SyntaxKind.ExpressionWithTypeArguments:
-                return !isPartOfTypeNode(node.parent);
+                return !isHeritageClause(node.parent);
             case SyntaxKind.QualifiedName:
                 while (node.parent.kind === SyntaxKind.QualifiedName) {
                     node = node.parent;