Thank you for the suggestion. Our intention when designing this challenge was to adhere as closely as possible to recent literature about best practices in challenge design and to the design of past challenges that were successful. The relevant recommendation of Reinke et al. from their MICCAI 2018 paper on challenges  is summarized in Table 2: “Feedback after a submission should not reveal information on individual cases”. Further, the highly successful ISIC challenge last year did as we are proposing to do, and did not make any results available until after the deadline.
Shortly after the August 1, 2019 MICCAI deadline has passed, the challenge will reopen for submissions indefinitely and the leaderboard will then update in real time.
 Reinke, Annika, et al. “How to exploit weaknesses in biomedical challenge design and organization.” International Conference on Medical Image Computing and Computer-Assisted Intervention . Springer, Cham, 2018.