Looks like they'll be run like Avalon4 and Avalon6 were, where multiple modules are chained together to a single RPi controller. The single-point failure part isn't so great, but since it's an off-the-shelf part replacement is super easy. Setup and configuration are also super easy because you don't have to track down IPs for every individual machine. Overall a pretty good setup.
Just like we saw with the ASICMiner Prismas, we're going to end up with a stable configuration and RPis are fairly cheap and easily re-sellable if needed. So buying 1 controller per 1-2 units is pretty reasonable to me.