Chiesa played more minutes (2500 mins) and matches (37) than Adeyemi (1700 mins, 34 matches) last season despite Dortmund played UCL until final.
Yes, Chiesa had ACL knee injury before but it seems he can recover and no major injury he got during last season. I dont see any upgrades apart whether it's true or not that Adeyemi will suit with Motta tactics better. But it also must be considered that Adeyemi will play in a new league, learn new languange, etc compared to Chiesa who already performed well in Serie A.