I think it is easy to underestimate how big of a deal this is. Matt has a stranglehold on Automattic and Wordpress, it is not possible to remove his control over the ecosystem and he is volatile. Ousting him as CEO is almost certain to cause a major reaction from Matt, so, for Automattic to make this decision is a very big deal. The right decision for the long term but the hard decision. I expect we will see Matt try to punish Automattic’s board, it will get worse for Automattic before it gets better.
Here is Matt talking about his control: https://news.ycombinator.com/item?id=42657150