Depends, Ebert may have given it three-two stars if only becuase he could be convinced in support social agendas in films (and given how he disliked gamers, maybe could have been convinced this was a GG issue (and I bet he would hate the fuck out of GG)). Still, he would probably be indifferent about it at the end and his review would make clear that is not that good and was mostly pity points (as some animated/comedy films got this treatement from him).
I doubt he would championed it with the intensity that half of film critics are doing, in any case.