They introduced the blockchain stuff mysteriously after there was a bug found in the randomizer device they were using. There were random numbers that were NEVER rendered even after 1000s of events.
If you check the draw numbers from 2018 and 2019 you will notice that the numbers 1, 4, 39, 53, 60, 66, 71, 79, and 85 are never drawn. Juniors in 2019 only had the #39 not drawn, but Cadet, Junior, and Senior worlds in those years had the other numbers not drawn.