Double Elimination Chamber

Here's the solution. We won't disqualify anyone. The draw is canceled, registration continues! I think I'll come up with something for the bracket. We won't disadvantage anyone. Hopefully, we'll get 64 participants :)

There's no need to cancel anything. Just draw participants as they register. Pair these two guys against each other, and everything will be fine.

Rigid brackets like in double-elimination tournaments aren't very suitable for Heroes tournaments; I've run into this many times – people like to register late, prolong matches, and can withdraw at any moment.

Therefore, in my opinion, a dynamic bracket is optimal, something like a Swiss system, but with elimination after 2 losses. This model has the advantages of both Swiss and double-elimination systems and none of their disadvantages. Plus, the number of rounds is smaller than in a double-elimination tournament, partly because you can pair a winner with a loser (if the number is odd), and it won't ruin the bracket.