Most noodles are pretty low in calories so eating noodles does not cause much if any weight gain.
So if you're on a weight loss diet and need to eat something then eating some noodles without any meats would be good for you to lose weight.
The noodles will keep you full and also aid in weight loss.
If you're looking to gain weight then eating just noodles is not gonna cause much if any weight gain because of the low calories.
You would need to add meats to the noodles to help increase the calories in the noodles.
Meats and other high calorie foods would help increase your weight gain more than the noodles would.