Wireless <> WiFi <> WiFi Direct
To be clear, disabling Device Connect does disable WiFi Direct, which is what the title of your feedback asked to be able to do.
Not sure what you are referring to as a "wireless broadcast", but once Device Connect is disabled, you will not be able to find/detect the Roku using WiFi Direct (or any other functionality that relies upon it, such as Miracast or Hotel & Dorm Connect).
You might want to re-name/re-title your OP to "Option to disable all wireless/WiFi output"
Just wanted to add that while turning off Wireless <> WiFi <> WiFi Direct settings sounds like a solution, its not a sticky config. If I wasn't clear earlier, i'll add now that this config gets overridden often with auto-updates and system reboots. Before using shielding faraday fabric, I'd get my entire network crashing down while i'm working, or streaming video, or my kids streaming remote classroom stuff. Having the uncertainty of network quality over wifi is terrible...so a solution that works for an nondeterministic period of time isn't that great.
Sure - "wireless off" needs to survive reboots/restarts/firmware updates (but not network connection resets or factory resets).
