The first to make it out the gate is not the Media Mod (which I am particularly eager to try). Instead, it's the $50 Light Mod. It might not be quite as exciting as the Media Mod with its built-in shotgun mic, or the LCD Display Mod, but it does give us a (well-illuminated) glimpse at where GoPro is going with this whole thing.
GoPro-friendly Light accessories have been available from third-parties for years; I've recommended some of them before. GoPro's take isn't revolutionary, but it does feel more coherent than some of the alternatives on Amazon. For one, it's very small, so it won't feel like you're attaching a DSLR flash unit to your GoPro. At 200 Lumens, it's bright enough to illuminate you and your immediate surroundings at night, but you might want something more powerful if you're shooting beyond arm's reach. It also comes with a silicone cover that acts as a diffuser so that it's less harsh on your face as you peer into it, with four brightness settings. The battery is built-in (it charges via USB-C) and GoPro claims upto six hours of use. The Light Mod is also waterproof to 33 feet, just like the Hero 8 Black.
What's most apparent is that GoPro sees this as a tool primarily for vloggers. The size of the Light Mod makes it versatile enough to be worn on the body, but also it'll sit discreetly beside, or on top of your GoPro without adding too much bulk and weight (though, again, you'll need the Media Mod for that). Before HyperSmooth, walking and filming yourself with a GoPro meant adding stabilization in post (or using a pricey gimbal -- which sometimes got ugly).
The Hero 8 Black is stable enough at source that often just holding the camera in your hand will be good enough for run-and-gun vloggers. Expanding the camera with better lighting options and improved voice recording (per the media mod) is a clear attempt to bolster its appeal to those looking for a pocket-sized "rig."
Until that media mod -- and its cold shoe -- comes out though, you'll need to mount the Light Mod independently. Given that it's compatible with almost any GoPro accessory, you have plenty of options, but perching it on top of the Hero 8 Black isn't one of them, yet. There's also the price. At $50 it costs more than the bulk of the competition on Amazon, so you'll need to decide if the small form factor and Media Mod compatibility are deal sweeteners for you. If they are, you can pick yourself one up starting today.