On HN, when there's a major story unfolding over time, we apply the "significant new information" test: https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...
The idea is to have a new thread for each development that adds significant new information, and to downweight follow-ups and copycat stories that don't. In this way we prevent the front page from being flooded with repetitive stories and discussions (often low-quality ragey discussions, the internet being what it is), while making space for substantive new content when it arises. We came up with this after the Snowden deluge of 2013, when HN's front page was inundated with a lot of articles that didn't make this distinction, and many users—even ones who found the underlying story interesting—complained.
If we apply this test here, it's clear that "China says ‘stay tuned’" does not count as significant new information. On HN there's no harm in waiting until the next important thing happens, and in the meantime we can turn our attention to other interesting things.