I actually don't know why this happened with the new menu, but none of the new dishes ever officially made it into print on a new menu. They make them from time to time as specials when ordering in, you just have to ask... For some of the dishes, they simply don't carry the ingredients all the time, so with a day's notice you could order ahead for a dine in special, if you have enough people to make it worth their time to do a special grocery store trip.
Also worth noting, the full menu has never been on their online delivery menu. Because the authentic thai dishes are more time consuming to make, they keep them for dine in customers only, to avoid longer delivery times and complaints. They will deliver the issan style dishes that are not on the online menu (isan sausgae, naem khao tod, etc) when you call in a delivery, but you should expect a longer wait for the delivery if you're ordering certain things.
Part of the secret of a success in life is to eat what you like and let the food fight it out inside.
-Mark Twain