Normally Indian players don't announce their retirements publicly or early despite getting clear mszs from the selectors due to their deals with ad agencies as it could hurt brands a bit. One of the reasons many cricketers delay their official retirements. Management does move on and reasons could vary from case to case but it's up to players if they want to announce or not. Even the likes of Kaif, Raina publicly announced their retirement quite late.
If I am not wrong then Dhoni did announce his retirement from tests in 2014-15 and in white ball cricket official retirement came around 2020.
Maybe because they believe they have the capabilities to play more and they do not want to retire too early. Most of the time subcontinent players do not announce retirement for this reason. But the problem is, the cricket board does not respect them well. I haven't seen many retirement announcements from sub-continent players where the board organized anything special for them.
If you talk about Bangladeshi players, most of them announce their retirement in social media or TV media without discussing anything with the board. The reason is, players wanted to continue but the board selectors never try to convince them.