The description of the Gift of the Metallic Dragon feat provided in the Fizban's Treasury of Dragons sourcebook states, in part (my emphasis):
Draconic Healing. You learn the cure wounds spell. You can cast this spell without expending a spell slot. Once you cast this spell in this way, you can’t do so again until you finish a long rest. You can also cast this spell using spell slots you have. […]
As a Cleric with this feat, does the last sentence mean I don't need to prepare cure wounds for my spell list, effectively granting me an additional prepared spell?
Best Answer
A cleric with this feat can cast cure wounds using spell slots without preparing it.
You have made the correct observation. The text of the feat is unambiguous:
The feat creates an exception for the cleric. Normally, a cleric must prepare spells to be able to cast them. However, the specific beats general rule tells us:
The feat provides a specific rule: it permits us to cast cure wounds using our spells slots. Since it does not say we must prepare the spell, we need not prepare the spell.