The night mode is for you to take pictures of foreground subject illuminated by your flash, while at the same time expose for the background.
If you want to take purely landscape pictures during low light or at night, use the landscape mode, which should be the 2 mountain peaks icon. In landscape mode, the flash will not pop up, as the camera will only meter for the ambient light only. Do take note that using this mode during low light will require you to use a tripod due to the low shutter speed.
And if I remember correctly, the other auto modes will pop up the flash if the camera deems it neccessary.
While we may say the using Av, Tv or M will gives the most control, the other auto modes does require you to have some understanding of their uses to make full use of their functions, and if you know how to make full use of them, it'll give almost the same results as the manual modes.