Key aspect of becoming a manager is making promises you may or may not keep. They cost you nothing, and when they come due it's the employees who suffer.
Sometimes, a great manager needs to speculate and do things at uncertainty and risk, while motivating their subordinates. They are clearly working to save the company in OPs case.
But alas, communicating earlier is when things have the most uncertainty. I have had great managers that set expectations around how much uncertainty and change is built-in to what they're communicating, but in general, the earlier they share something, the more likely it is to not be certain yet, still it's often useful information to have.
(I'm only speaking in general, not specific to this situation.)