This has been known since the promotion for Contenders skins began. The live broadcasts for China region Contenders matches are only hosted on the Bilibili platform which is not compatible to run on the Overwatch Contenders website embedded web player. There will however be a series of encore presentations of all China region Knockout and Playoff matches in the months of April and June. See my rewards-eligible broadcast list for details on when these matches will run:
I would also emphasize, there are going to be TONS of hours and opportunities to get these skins throughout the month of April as the bulk of the Season 1 2021 season of Contenders takes place in April.