No he is not reacting. All he is doing is changing players. Pjanic is gone so he plays Bentancur in his position and fills the rest of the positions with whoever is available. The obsession with regista is silly especially when your only player available to fill this position is Bentancur who has no idea what regista means. But it does not end there. Mandzukic is injured so he replaces him with Douglas Costa where the two not only are totally different players, they also have totally different mentalities. A mentality that Douglas Costa has no idea what it means to offer himself for the team. Now we are talking about two crucial positions for Allegri's tactics, I will talk about the third in a bit but let me point out one thing about what you said about the players playing a bad game. So we have now Bentancur playing instead of Pjanic and Douglas Costa/Bernardeschi/Dybala playing instead of Mandzukic. How do you expect those who are next to them to play when they are not doing what Pjanic and Mandzukic usually do? Yes, you confuse the hell out of them and consequently they make mistakes.
Then to the third position, you guessed it, Bonucci. He got injured and he used Rugani instead who happens to be a good defender but that's about it. A good defender, no drive and always strikes me as scared. Chiellini gets injured so he replaces him with MDS. I will not talk much about this department as it is not his problem we are short on defenders all of a sudden. That's on Paratici.
So what is it I am trying to say? In previous seasons with Allegri when things stop functioning properly, when we got injuries he changed formation and approach. He adapted the TEAM not the POSITIONS. This season he has only been changing players instead of changing system. We tried 4-4-2 at a couple of occasions, it gave fruit but he reverted back to this dysfunctioning 4-3-3.
The fact that we have pulled one shot on target in two consecutive matches says a lot.