There wasn't anything they could say in that post that would make people feel better. They're still reeling from this week's events, and I'm sure that whatever plans were in the pipeline are now in complete flux as they reassess the game and figure out what exactly they're going to do from here on.
At the very least, the parts they touched on - acknowledgement that they've lost the community's trust, diving into feedback for Lightfall and its seasons, needing to make sure The Final Shape is among Bungie's all-time best games, etc. - are a bit reassuring for me in the short-term. Ultimately, more needs to be said and shown from them, but... again, I don't think that's possible at this exact moment in time. Not when employees are still dealing with the fallout from Monday, and when they're probably upending their existing plans for the game in favor of something that will hopefully be better.
Just have to wait and see what they say in the coming weeks. It sucks, but that's just how it is. What matters is that the employees are taken care of.
EIDT: Christ, they weren't advertising the expansion in this post. They were emphasizing that it needs to be great if they want to regain trust, which is true. Some of y'all are too fucking cynical.