Bangladesh have beaten New Zealand in home conditions earlier as well. So their victory in the recent one-day series wasn’t surprising. They had also given the Kiwis a close run in the Tests that concluded prior to the one-dayers.
If Bangladesh were told at the start of the series that their two-Test match series at home against New Zealand would have ended in a draw, they would have been reasonably pleased. After all, the Kiwis are still a much stronger side as compared to the hosts.