Exactly.
I thought this was pretty obvious. The WH staff can get in legal trouble for giving preference to certain media outlets over others. Therefore, the GOP had to host it.
The awards were effectively a slide show, as any use of cameras and equipment would require Secret Service assets and resources.
It was a bait and switch. Trump just had to tweet the link and the GOP just had to 404 the stream that never was. Fucking awesome, honestly.