Yes, last season would be a very bitter reality considering that Juventus had to be sanctioned with a point deduction at the end of last season so they had to drop from the top 4 to fail to get a UCL ticket, after all they didn't play badly last season but they were a little frustrated considering the sanctions they received. I hope also that as a Juventus supporter next season they can show that they can win the league or get a UCL ticket to qualify for the top 4.
Yep. It was a nightmare for Juventus, the sanction made them lose many points and decrease their motivation. After they got the sanction, I felt their performance was decreasing a lot, it indicated they didn't play with good motivation to win. They must think if there is no sanction, they must finish the season in the top 4. Sure, everyone expect that Juventus will perform better again and return to UCL zone. I'm sure Juventus has the capability to return to its best shape if they buy some good players to strengthen their squad during this transfer window.
I know last season was Napoli's season and they played very consistently and well but it's unlikely they will maintain it next season considering their coach left Napoli and was replaced by a new coach, that's why next season there will be a lot of tough competition so the struggle for the top of the standings will be getting hotter.
Since their coach was leaving the club and some key players probably move to new clubs, I also think it is difficult to maintain good performance as the last season. However, I believe Napoli still can stay in the top 5 of Serie A table, they still have enough players to compete for UCL or Europa League zone. It is unfortunate that they lose their coach and key players.