Does Xoom automatically detect renames?

The answer is no. Xoom is unable to detect renames because Key isn't environment-independent.

When an item to be deployed shares the same Key as an item in the database, this may well indicate that the item has been renamed. Alternatively, it may be a coincidence, caused by the contingent ways Keys were assigned in each environment. As Xoom has no basis for deciding which is correct, it assumes that these are two different items that happen to share the same Key.

Should you wish to rename items, we strongly recommend that you use Xoom Reset Helper, a tool that helps you perform a logical and consistent rename without the risk of accidentally introducing bad references.