Yes, I know the test footage was just a pitch to FOX so they could make the film and the movie likely won't be CGI. But here's why I think thtat could actually work.
1. They (Could) Make Alot More Money
Animated/CGI films are more of a medium for children and family films sure. However, this film could break the ground for being a successful R-Rated Animated film. That being said, fanboys would flock to the theater a thousand times over to see the movie. Animated movies tend to do better at the box office and make their money back despite costing more than live-action. If they market the film right and perhaps release a PG-13 version as well as an R-Rated version then this film could do way better than it could live-action. Families are WAY more willing to let their kid see an animated head get cut off than a live-action one. It's fact that animated movies can get away with alot more as a more playful medium for TV and film. The slapstick could go miles ahead which brings me to my next point.
2. There Can Be Way More Violence
A live-action Deadpool movie can be violent as ever but an animated film can literally toy with things that live-action cimply can't do and do things better than live-action. CGI can get realistic so it's not like you would sit there thinking "I'm watching a kiddy Deadpool film" you would sit there thinking that this is a Deadpool movie done to the best of anyone's abilities. Sure, Reynolds can leap from a roof into a speeding car but CGI will require less physical work while also being more convincing. Deadpool isn't a 'set-in reality hero' anyway. I've always said there can't be a better Deadpool movie than that Deadpool game so why not try to rekindle that? Reynolds and the writers over at FOX have already proven they can bring more than enough funny to the character for a film.
3. Scheduling Won't Be A Problem
Reynolds has stated he's attatched to the film. This doesn't neccesarily mean he has to do the movie live-action. Reynolds can do the voice work and mo-cap for Deadpool and be done quicker than he would if he were to do the whole thing live-action which won't bring up scheduling confllicts. Plus if the film is well-recieved he has a spot at FOX for the Merc and can return for a live-action run at it if that's what the fans want. Reynolds wouldn't likely run DP into any of his other projects if they were to do the CGI version.