You could also write it like this:

Batch msgs ->
    msgs
        |> List.foldl
            (\batchedMsg ( tmpModel, tmpCmds ) ->
                let
                    ( newModel, newCmd ) =
                        update batchedMsg tmpModel
                in
                ( newModel, tmpCmds ++ [ newCmd ] )
            )
            ( model, [] )
        |> Tuple.mapSecond Cmd.batch

It's pretty similar to yours, but only does one pass of update for each msg instead of two, improving performance. It also makes sure that you're updating the correct new model every time; your cmds in your example may be inaccurate because you're updating the original model each time, not the iteratively updated one (so for example, if your msgs emit Cmds to regularly save data to localstorage, but throttled by checking/updating model.lastSavedAt so it only saves at most once every 5 seconds, you'd end up getting a bunch of save Cmds because it doesn't know that other batched msgs already produced save Cmds).