You clearly have memory gaps. We werent outplayed by Ajax at Amsterdam. Before Cancello made a brainfart we looked comfortable and looked like we would win the tie. Then injuries happened like so many times for the return leg. Ajax almost made it to the final that year so its not some random team that knocked us out, like Mura.
Milan were never favorites in that tie, they were on a downward spiral unlike Spurs.
In the years that followed Milan spent the next 10 years reveling in mediocrity. You make it sound like Allegri was in charge of the all time great Millan side while in reality they had 36 yo Seedorf starting their games.