I didn't test it in C2, but I did end up testing it in C3.
I used TextInput and saved it's value to a local storage key.
Then every 5 seconds it would get the item value and set the text of a Text object and a SpriteFont object.
Turns out the emoticons work with Text objects and not SpriteFont objects.
I exported to mobile to be sure, with same results.
Emoticons will display correctly with Text Objects.
Emoticons are treated as a space with SpriteFont.
test test = test test