Ralkage I understand this. But you don't have to reset to actually... reset. The upvotes and downvotes are just numbers. It is convenient for us to show everything that is in the database, but ignoring everything before April 2020 isn't that different than deleting existing data on April 1st 2020 from the user's standpoint. In both cases you just change what you show.
But I agree, it's a bit more advanced and unsure if anyone would want to spend time developing it instead of just wiping (if you don't need the data).