Well, https://api.overwatchcontenders.com/teams seems to return some data, and once I turn off my adblocker, https://overwatchcontenders.com/en-us/teams even seems to use that data to display information about team rosters, but there doesn't appear to be any documentation, so the API could change at more-or-less any time.

When/where did they talk about the re-seeding? If on-stream, what segment/time; otherwise, what URL?

Edit:

Well, I guess they were always going to do the reseeding: https://twitter.com/overwatchleague/status/1108805481571778562 has the information but for some reason also a misleading tree.

They hadn't redrawn the tree after the SEO/NYXL match, but of course at that point, who would have been surprised if Boston had pulled off the upset too, which would have rearranged the tree in a DIFFERENT way.

Actually, after the BOS/VAN match, they still hadn't redrawn the tree, merely filled in the teams for the "highest vs lowest" match.

Why did they even draw it like a tree?????