An article that mentions a timeframe of “the next few hours”, but doesn't have any timestamp besides a date without a timezone.
“I (name the individual accountable) will give you an update at 12:00 PT (name a time) as an update to this post (name the communication channel) with the current status and latest information on this issue (don’t promise time to resolution, just time to info).”
Simple, clear, concrete, and unambiguous. I had hoped that Firefox had better communication procedures in the event of global-impact P1 issues.