He definitely struggled against Monza but he was better than recent Rugani or Bonucci his other appearance so far. You'll notice the statement you quoted doesn't say "against Monza" but includes all his appearances. His 90 minutes against Spezia were quite good and he was dependable.
Reading comprehension is important.
You talk about reading comprehension, but how about comprehension of games and performances?
Like when has ever looked better then Bonucci? I cant stand Bonucci on personal level, but to say Gatti is better already and performing better is wishful thinking. Gatti has barely played so far, but looked shaky in pre season, and straight up awful vs Monza.
So when has he looked better? Spezia game alone? Bonucci has had several better performances. So How is he elevated to higher quality tier status then Bonucci?
Rugani has been bad to mediocre for years so preferably should be last on pecking order. But he has had several solid to good outings this season so far, performances near on par with Bremer. So for him too, has to be asked, when has Gatti shown he is better in Juve shirt?
The performance vs Monza alone was so bad, one of the worst a Juve defender has had in a while, that it legit should explain why Allegri has had him as last in pecking order so far. He is untested player at this level who has alot to prove still. So forgive me if I doubt the notion of him being handed a high status as a player, without the performances to back it up so far.