Wrong. There are card types, and then there are creature types. The card types are:
Land
Sorcery
Instant
Enchantment
Artifact
Creature
Tribal
Planeswalker
Some types can be combined, and then there are also supertypes. So, by todays rules, there's no such thing as "Creature - Legend" like we had in the old days. "Legendary" became a supertype, so every such creature received errata to read "Legendary Creature - ____", as they decided that simply reading "Creature" did not suffice anymore for flavor and design reasons (to which I agree). Same happened with artifact creatures, since they decide to do this change in templates. So, if you go into gatherer and look Ornithopter's older versions, it reads "Artifact Creature", while nowadays it reads "Artifact Creature - Thopter". So artifact is a CARD type, not a CREATURE type, and changelings do not affect that. Also, this change in the rules was what got rid of the "Wall" type. Back in the day, "Wall" ALREADY meant the creature could not attack, but nowadays, all "Walls" received errata as to also have defender (check Mistform Ultimus first printing, his reminder text, and the latest one in Time Spiral). Otherwise, by the old rules, not only changelings would not be able to attack (they ARE Walls after all), but also they'd all be legendary (since Legend was a type).
Mycosinth Latice will do the trick, though.