It would lower the operations costs of hardware, hopefully (that's the entire goal of this article) but you'd need more people resources to manage it, I would guess. Mesos and containers automate a lot of thinking work.
Once you move to hosts dedicated to specific services, as seems to be the suggestion here, you also might increase the overall hardware cost across your set of services. The cost per some of the services might decrease, though.
It would lower the operations costs of hardware, hopefully (that's the entire goal of this article) but you'd need more people resources to manage it, I would guess. Mesos and containers automate a lot of thinking work.