I think what they should have done is offer an alternate nightfall to people who don't own the DLC. Obviously people will attempt to exploit it by playing the DLC nightfall and temporarily deleting the DLC to play the secondary nightfall. Although, there would be an indicator detecting if they already completed a nightfall for the week that they couldn't attempt to do the second one.

I also completed the VoG on normal mode again today. No chest piece. Just boots, energy, shards, and Chatterwhite. I can't do HM because everyone on the LFG site is looking for Lv. 30 experienced players.