Tamim Iqbal is now the captain of the Bangladesh ODI team. And I think he might now want to focus more on the ODI format. And so he is distancing himself from T20 and Test format. Bangladesh wants to qualify for at least the semi-finals of the upcoming ODI World Cup. And so it's time for Iqbal to do better in the ODI format to make himself more useful for the team.
Bangladesh has done well in ODI format recently. If you check the points table for ICC Cricket World Cup Super League, they are at 2nd position with 12 wins from 18 games. England is ahead of them by just 5 points. Their weak points are T20 and test cricket, and for now we can ignore them. If the main players such as Tamim, Litton, Shakib and Mustafizur remains in form, then I don't think that reaching the semi-finals will be a big hassle for them. Also, the conditions will be familiar for them, as the tournament will take place in India.
You are right. If we consider only the ODI format, then it can be said that Bangladesh is a strong team. And Bangladeshi players are consistently performing well in the ODI format now. And so Bangladesh can reach the semi-finals in the 2023 World Cup, if they can continue this streak. And I would say Tamim's decision is right. If he concentrates completely on the 50-over matches, we will get better performance from him in the World Cup.