Robot production lines need robot technicians to support them. I doubt you'll find many of those in Bangladesh any time soon.
And one robot replaces 17 workers, it's probably around 1 robot tech to support 10-20 machines.
According to these stats [1], in Bangladesh there's 4800 factories with around 725 workers on average. So that would be 40 machines with one worker each to supervise and 3-4 robot techs. 5 people to replace 725!
i guess that time window is how long the automatic t-shirt making business remains viable in the US.