Sounds like an interesting concept. You have links to more information? I used to like MST3k and I enjoy Riff Trax, plus I watch/listen to people watch a bad movie and then review it (The Flop House or Half in the Bag).
A show like this is entirely dependent on the people doing the narration. If they have no chemistry, or no interest takes on the material, it will be incredibly boring. Luckily it's the internet and we can immediately switch to something else.
I've never seen them before so it could very well be terrible, but their comedy videos looked fine.
I don't really watch RLM anymore aside from plinkett reviews, and I've never been a big fan of MST3K but if that's the kind of thing you enjoy I'm sure it's what they'll be doing. Apparently they've trolled multiple morning news stations as well with various acts.