I've watched the post match press conference (with Italian to English sub-titles) to try to get to the bottom of it!
He was asked about what lessons he'd learnt from this season. His answer was along the lines that we are doing better than last year when you take into account the high number...
Italy are reporting De Zerbi as saying... “Let’s see if we can reach an important goal again, then next year whoever is here will think about how to improve on this season.”
https://www.footitalia.com/gazzetta-de-zerbi-likely-to-leave-brighton-this-summer/