Adding an answer choice during distribution - choices uploaded in Excel

ras_wes_org - I believe this is a Drill down question. If yes, we can't edit such questions as it may impact collected data.
Best practice of dealing with such questions is that always store data of drill down question in embedded variable which can be used for reporting instead of actual question. If you are already following this approach, you can simply create new question and have display logic on both questions(in your case this logic would be based on current date- if current year is 2021 show first question otherwise second one).
If you already don't have any embedded variable to store final data, you can create it now and in survey flow pipe-in these variable from both drill down questions. In this case you will have to back fill those embedded variables for already collected data either manually or using API.