Basically this seems to work:
data = Style[Row[{"data = ", {1, 2, 4, 8, 16}}], Blue, Bold];
nb=CreateDocument[
{TextCell["Some data","Chapter"],ExpressionCell[data,"Output"]}
];
SetOptions[nb, "ClosingSaveDialog" -> False];
SelectionMove[nb, After, Notebook];
NotebookWrite[nb, Cell[data2, "Output"]];
But it will not satisfy your wish below:
Only when the user edits the notebook himself, he should be prompted
to save as usual.
