The other one links to www.tensorflow.org which has no information about the release yet.
No it didn't have a thread going; the other link was literally posted less than 30 seconds earlier. I agree that comments are best kept in one location though :)
I'm writing this because I actually take great care not to post dupes, and try my best to respect other HN users' submissions. If there was indeed a discussion going on the other submission at the time I'd likely have deleted mine, and posted the better link (IMO, at the time) as a comment instead for mods to update -- sort of like I did here: https://news.ycombinator.com/item?id=13654806.
In the end it's up to the community (and especially the HN heroes/warriors scouring the "new" page for gems) to vote for the best content and so it can get a shot on the front page. Time matters sometimes and HN users who find and submit good stories early deserve credit for it, but to me content quality matters more (particularly when the time diff between submissions is low).
When I see two or more stories covering the same interesting topic/event on the "New" page, I'll typically look at both links and vote for the highest quality/most substantive one.