Your understanding is WRONG. Visas have to be issued by 30 September 2020. Entry has to happen before the visa expires, which is anytime up to 6 months from issue. You think someone who gets a visa on 30 September is expected to have entered the US by that evening, possibly from the other side of the world? I am a great example, DV2013, visa issued July 2013, I entered December 2013, a quarter way through the following fiscal year. Please don’t spread false information, especially the type that can cause people to panic for no reason.
And why on earth would they need all 2020 winners to have relocated before they start the next year’s process?