You have to first clear the table and then add new data using row.add() function. At last step adjust also column size so that table renders correctly.
$('#upload-new-data').on('click', function () {
datatable.clear().draw();
datatable.rows.add(NewlyCreatedData); // Add new data
datatable.columns.adjust().draw(); // Redraw the DataTable
});
Also if you want to find a mapping between old and new datatable API functions bookmark this