I'm not saying it should try to predict the future differently, I'm just suggesting that if the prediction is not reasonably accurate it is not worth broadcasting in clear terms at the top of the screen.
The further in the future you try to predict, the less accurate the prediction is. I presume this is the main reason the time machine itself is limited to 48 hours. Even then, it is typically pretty inaccurate beyond 12-24 hours since other players are pretty good at changing the game state.
My main issue here is with the notification going beyond the normal 48 hour time machine window and suggesting something that is likely pretty inaccurate at the expense of whatever player happened to build a mine first.
I agree that charting would be a good solution to this.