You could also add England into the mix and use their improvement over the last four years to back up my point.
England were embarrassingly knocked in the group stages by none other than Bangladesh in 2015. They were so shit, you'd argue they were a worse ODI team than Bangladesh at that time. 4 years later, one has made such great strides and, as Sri Lanka did with Jaya and Kalu, they've changed the standards in the limited form; with the other we're still waiting for significant signs of improvement. Look at all nations, bar maybe New Zealand, the rest have had periods of actual domination - Bangla have been around long enough to show more signs of consistency.
This will be my final post on this matter. We can judge them after this tournament.