While "Built-in Chromecast" can be finicky on x86 ports, many builds support 3rd party casting receivers.
To locate and analyze this specific artifact from an ATV9 IPSW/ISO:
The inclusion of an x86 top binary in the ATV9 ISO acts as a diagnostic breadcrumb. It confirms that the tvOS build system is generating split-stream binaries or "Fat Binaries" for internal validation. For the enthusiast and developer community, this provides a potential vector for running Apple TV software in standard VirtualBox or VMware environments on standard PC hardware, bypassing the strict ARM hardware requirement for preliminary OS exploration.
To anyone else, it was gibberish. But Leo knew the legend.