I am fine to go for this change, to add contact records at the end of the list. I can't think of a case where such update could break/change exiting behaviour badly.
Just some aesthetic remarks, use snake_case function naming format, it is how the other function in the file are. The, then me should be somehow related to the context of the file, not being a generic one for adding to a list. As an example, it can be called contact_append(...).