So here's the deal with this.
Jeff Sneider has always been a very weird/ creepy guy, but at one point he had a lot of sources and would break info and leaks pretty frequently. Over the last two years his hit rate has plummeted and he has had several major meltdowns on Twitter when he gets called out for peddling bullshirt.
On top of this, he was not invited to the Superman trailer press event by James Gunn. Sneider used to be seen as a more legit movie journalist but he's now more regarded as a peddler of snark and bullshirt. He apparently was livid he didn't get invited, and then suddenly he's "hearing" the movie is a "mess", something literally no one else seems to have heard or reported. He also claimed Gunn fired the VFX teams, which Gunn immediately and publicly called BS on and Sneider had a meltdown over that.
Additionally, the only test screenings that have happened are friends and family screenings. These people are not running to tell a washed up rumor monger about the quality of the film.
John Rocha knows nothing. He has no sources. He is a former podcast guy from Collider who has claimed to have "sources" for years while having a hit rate on leaks and rumors that is nonexistent. He can be summarily disregarded in any and all movie discussions. He mostly just panders to Sneider.
ViewerAnon, who is a very credible leaker with an established high level of accuracy, has said to disregard all reporting (positive or negative) about the test screenings, as they were strictly friends and family screenings and nobody has really heard anything. Not that it would even matter because the movie doesn't release for 8 months and will change many times between now and then.