The test screening reports seem to be a case of circular reporting, there’s a few articles about positive test screenings but they all seem to link back to a single tweet from DisInsider. Disinsider tweets it, then Snow White News quotes them, then Inside the magic quotes snow white news, etc.
From what my Google search found they all link back to this single tweet...
“Rachel Zegler reportedly BLEW audiences away with her performance as Snow White a scored very high with viewers in a test screening!! Gal Gadot and Andrew Burnap also got high scores during the screening for their characters!
Via @TheDisInsider/@SkylerShuler”
All that to say the “positive test screenings” may have been accurate or a total fabrication.
ETA… it’s also interesting the tweet mentions specific characters rather than the overall movie, maybe the test screen reviews said Zegler, Gadot, and Burnap were fantastic but the movie itself fell flat so now Disney is building a better movie around the parts that worked and reworking the parts that didn’t work? We’ll probably never know.