Their performance is average even with the deduction. It is an ok performance for them. They have been a club for several years to score 90 points and even more than that per season. So even if you add those deducted points back, they wouldn't make it 90 points. They have performed below par and now I wonder what they are going to do to improve the squad for the upcoming season. First and foremost they must try to qualify for the Champions League or otherwise it will be hard to sign any stars. Nobody will go there and not be able to play the Champions League.
if it wasn't for the point deduction surely juventus would be the second team to perform well in serie A this season. but the scandal that hit their team made them get a penalty from the FIGC which made Juventus slightly off balance in the standing table.
Allegri is a great coach he was able to get Juventus back to a good ranking in the standings table where they were almost able to get into the top 4 because the point difference is not too far from the top 4 teams.
juventus still has 2 chances to get a trophy this season namely in the Europa league and in the Italian cup. well, most likely Juventus will focus more on all their strength only for the Europa League and improve their ranking position in the Serie A standings table.
Everything is possible for Juventus Turin. They have two ways to qualify for the Champions League, which I believe is the most important goal for them. A season without Champions League is rough as it has many consequences. Some players want to leave and are easier to get for other clubs who play in the CL, and other players that Juve would like to sign will certainly think at least twice about their decision. These guys don't want to waste a season without playing CL if they could do so otherwise.
Still I stick to what I said that this season is average or maybe a bit above average if we add those 15 points back. But they would still be so far behind Napoli that nobody would say this was a great season.
For the future I hope that these shenanigans within the club find an ending. I am not particularly a Juventus fan, but it's boring when the leagues get boring especially because of one of the clubs getting a penalty. That has nothing to do with sports.