I approve of the new rule, although seems like a pain in the butt for everyone
Hopefully it's effective at catching malicious cheaters, however it's impossible to verify that the deck sent to you was the one played in the match, as you can't show it to the other player without ruining the tournament. Giving away opponents deckcodes is frowned upon even if you've already played them.
I don't think it's in anyones interest for people to get 0-2 losses because they used an illegal deck twice (except the opponent), and I do believe the fact getting a loss first game because of an illegal deck should give you the opportunity to correct your deck in the next game which it currently does if caught early. Would it be possible in the case where the same mistake was made twice in one match, and the result was like 2-0 or something, for some kind of replay starting at 0-1, or would that just not be possible in terms of how the event is run?