Sharepoint modern List choice column with dynamic values

Hello, what if after creating the initial dropdown dependency that writes back to a SharePoint site you have to totally update the list to a new or revised list.  I think per a test I made that changes to update the cascading dependent dropdown list that it then affects the existing SharePoint's entries on that same field.  - How does one update or replace a field with such dependencies and have it NOT mess up the historical information in the Sharepoint field? -- I see nothing in Microsoft about how to handle these edits (as things change over time). e.g. one of my fields changes each new fiscal year so what was a choice one year is not the same as the next.