Although this is Ajax's home match, I can't call the Ajax team as favorite. Because Napoli is playing very well this season. Napoli has won both of their Champions League matches, scoring 7 goals and conceding just one. Besides, Napoli is playing very well in Serie A. They are at the top of the table. Since Napoli can continue to perform well consistently, I don't think they will be defeated against Ajax.
The only advantage in this match for Ajax is because this match was held at their home. Of course this will have a positive impact on Ajax. But as you said. that Napoli are indeed at their best. their form is at its best this season. and they consistently maintain their performance. so I still predict that Napoli will most likely win the match. or at least a draw could happen.