Considering pretty much every single one of the delays was directly caused by the director, and the team itself went to pretty extreme measures to still meet all the product deadlines, then if the schedule is such a worry then assigning a new director might actually be a better idea.
Christina clearly knows how bad Hazuki is at keeping to schedule, and even outright mentioned it to her face at the end. So it seems a bit inane to mention how a new face might not be able to keep to schedule, when the alternative you want overseeing it is Hazuki.