Think about it.
Sefarim say that taste of food comes from the nitzotzos of kedusha in the food.
If you compare chicken soup before adding kneidlach, to chicken soup after you add them you will realize that matzo balls must be full of nitzotzos as not only do they taste good themselves but they add flavor to the chicken soup around them.
Therefore kneidlach must be very holy.
I think you can bring a proof from here that someone who usually eats two matzo balls should not go down to one, because ma’aylin b’kedusha v’ein moridin.