No I don't see any adverse side effects, aside from slightly added noise
The cover is thin plastic, your drive train is all metal. Your drive train will cut through your finger without breaking a sweat.
Plus the whole "gaurd" moves with the chain.
Pretty nifty idea actually. It's basically a very slimmed down version of a dutch bike chain cover.

All that said, I would never use one, proper chain maintenance is the way to go.