I understood the example, and it could be a minor hiccup there, but the essence is different:

By having a structured context of the key session discoveries, decisions, rejected items (if there were past commits with decisions that had been rejected, etc..) you achieve a type of contextual storage of the reason, thus after a month, when a team member wants to start working on a task that you have touched, and now forgot since you are doing ai-assisted coding and pr throughput is to sky right now, your collegue at least will know the rational behind the decission and working with his agent, the agent will produce more reliable code not introducing something for the sake of solving the task.