Read any article regarding agile software development, and you will find that the importance of sharing information is emphasized in most cases. SAFe (Scaled Agile Framework) has transparency as one of its core values, with many of the practices and ceremonies hand-crafted to promote and facilitate it.
In reality however, it is easy to prioritize other tasks which are interpreted as more pressing in the moment, and not spend enough time on sharing information or making it available in an easily consumable way. You simply get caught up in your more important day-to-day tasks. Before you know it 3 weeks have passed, key decisions have been made, and key people have not been notified. Suddenly parts of the team are working based on obsolete assumptions.