From my experience, sharing is mostly bad.
Very often, you'll be tempted to share good news too early, and very often it won't materialize (startup life is a roller coaster)
This alone will erode the morale of your team.
But there is an other factor, many humans, when presented with data and problems, tend to at least think about solutions, and they dislike being ignored.
Their solutions and ideas might be good, but they are very often half-baked and everyone has different ideas and priorities.
In practice, when people are asking for information, they implicitly are asking for power.