These are the qualities of a good defender despite it a foul should know when to take decisions,off the ball and with the ball,trust me Sergio Ramos will even do more than this.You can see that almost resulted to a goal,but great the tactically fouled Saka.
Mourinho is the best coach defensively so he'll definitely see nothing wrong with this decision Chiellini did.
There is a give and take to that situation and that is the risk a professional player takes. In that situation Chiellini could have seen a red card, it was a position where it could have been a proper goal, not guaranteed of course but there was a very high chance, so the ref could have given him a red card, which would have made the situation a lot worse because Italy would be playing 10 player from then out and that may have changed the result of the game big time.
This is why I believe that we should not praise his move, but also not condemn it neither, of course a defender would do everything to prevent a goal, unless that is a move that injuries another player and we all know there were nearly no injury risks with that move so I totally respect it, he realized he wasn't fast enough so he just yanked his shirt, as long as he didn't get a red card, that is a good move.