Will a blank candidate source automatically update?

Summary: Will a candidate profile loaded via HDL w/ no source, update if the candidate reapplies?

Content (required):

Hello all, we are loading candidates into ORC via HDL. Some will have blank values for Source, Source Medium on their candidate profiles and job applications. If that candidate reapplies via ORC, will the Source on their candidate profile automatically update?

Version (include the version you are using, if applicable): 22B

Code Snippet (add any code snippets that support your topic, if applicable):