At the end of the season, the Inter Milan team was quite stable as a team. Despite not winning the Champions League or the Serie A title, Inter Milan was the most consistent team in Serie A at the end of the season.
It is the past season and they can not live with pride from the past. We see how things changed with Leicester City after one season and they just demoted to English Championship after the past season. Two seasons ago, they went to semi final in UEFA Conference League.
And so they don't need much change within the team. Too many changes could make Inter Milan's performances erratic again. Inter Milan should keep the attack and midfield unchanged. and buying experienced defenders to bolster the defence. Only then, I believe that this team will be able to perform well from the beginning of the next season.
I disagree that they don't need to buy new players because they are facing with risk of losing some important players. If those players leave the club, they must buy new players to try maintaining their strength. They have to be more actively on transfer market but it is no guarantee that they will get successful transfers and great performances from new comers.