I just want an answer
There is nothing to release. Grab it from a NUS downloader of your choice, and use https://github.com/noahpistilli/WiiFitBodyCheckChannel to generate the SD card file for it.
What about the WAD? Where do I get that?
You can get it from any NUS downloader. I personally use NUSGet.
I found a WAD of the body check channel, but when I load it up, the screen goes dark and my wiimote turns off.
Is this normal?
yeah its normal but the wiimote should be turning on after like 2 to 10 secs and the black screen should be gone after loading the channel if not, maybe the WAD is missing some files or the WAD didn’t install correctly.