Gundogan left before Palmer left and it was known for months. City signed Doku when they had Palmer. They allowed Sterling, Mahrez and Gundogan to basically leave the club and Palmer was there. Grealish had reached his ceiling.
Pretending that people finding the decision “confusing” is a red herring.
Selling him was a monumentally stupid decision that genuinely did not need to be made at that time with the players city had, the players that had left and those they subsequently bought. Just call it what it is.