DY: Rather than relying on the Gilyon Maharsha or the Badei HaShulchan, I suggest you look up the Tzemach Tzeddek (HaKadmon) inside. It’s been a couple of years, but I’m pretty sure he writes what I said in his name.
I don’t understand that point from Rav Shachter either, though I would be uncomfortable telling someone to eat it with a hamburger because it lead to Takala. One could anticipate that rumors will abound that all Entenman’s products are really Pareve, which is presumably not true.
It would be Batel because it is only a Ta’am Kalush, and only Milsa d’Avida l’Ta’ama is Assur when less than 1/60. Reb Chaim (Brisker) brings a beautiful illustration of Ta’am Kalush. If I made a stew with 61 ingredients apportioned evenly, would it be tasteless? Each individual flavor has 60 against it, and the end result should be water. Obviously Bitul b’Shishim does not mean it imparts NO flavor, just that whatever it contributes is Halachically insignificant.