Well, ahasja, I would rather keep the timeline concise and restrict it to entries/events with a more or less solid foundation. It should also be more focus on the future than on the past. Past events are okay – and if only to find links to news releases quickly and in context. There's even a tab for past events. However, past expectations are something different than past events.

However, I am open to suggestions. If here's much support for your proposal with some good reasoning, I might change my mind. Anyway, you can always take your periodic snapshot to be able to detect and keep changes.