All I can say is I don't think it's fair to judge a scene or full movie if you haven't actually seen it. There have been many times where I was excited to see a movie or TV show, and was greatly disappointed by the finished product. And there have been times where I wasn't excited about a movie or TV show, but found it surprisingly enjoyable once I actually watched it. The scenes with Lynch and Ryan may wind up being memorable, unlikable, or just plain forgettable, but there's no telling right now. And yes, I agree, the two DC stars look genuinely thrilled to be working with the Muppets.
And yes, everyone's entitled to their own opinion. So please respect other people's thoughts.