One of the obstacles Juventus still can't sack Allegri is the severance pay if sacking him is still too high, but I'm not so sure about that.
Likely it is a biggest or one of main reasons why Juventus are still very patient with Allegri. Compensation cost (if they sack him) is high and put the cost into current finance of Juventus, they are smart enough to delay it. They likely will be derank to Europa League but in Serie A, they still have chance to climb up and compete the season in top four.
Because why keep him but destroy the team's performance and achievements, so of course Juventus must be willing to spend money to sack him because their pride is at stake here.
Juventus know that if they sack Allegri, they must put the club into hands of a new coach. There is no guarantee that a new coach will be able to sort out this crisis. Allegri has had many seasons in Juventus and he understands about the club deeply. A new coach is not familiar with many of things there. I believe Juventus will give Allegri more time and they will make decision after the World Cup that ends in December.