Very astute. The markers are linked to time for a reason. Q needs people to believe that he is the real deal, and we are the ones that are going to help prove this to as many people, so they can pray for the mission to be a success, and help others believe too.
How you prove that something is real takes into many factors. The authenticity of the source has to be fully established before his words are to be written into history as the truth. And the bigger the source, the larger the amount of veracity needs to be established. Using the timings of previous words to show future words or news is key to showing the power of the man uttering them. But many things cannot be revealed in the way people would like, or at the time they would like - ie right now. There are always multiple factors that the enemy could use to dilute or poison the message if too much was revealed in advance. By dropping hints he shows his power when revealed. And when it finally is, we see it raw and unfiltered, free from damaging narratives that could lead others astray. As for disinfo. Maybe some things need to be shown to the enemy to divert them. But also some things do change, and plans change also. A man may have power, but so do others, and he must be flexible.