Bangladesh will easily qualify as the match is played in spin friendly pitches in the UAE. The main issue is see with New Zealand is that their main players are rested and they cannot come out and play well without any match practice.
Nothing is guaranteed, especially if the format is T20. The advantage for Bangladesh is that two of the teams from each group in the qualifying stage will progress to the main tournament. So they can afford to lose one match. They are in a relatively easy group, along with Papua New Guinea, Scotland and Oman. Of the other three teams, PNG has been in pathetic form recently. Oman do have the home advantage, but their players lack experience. Only Scotland has a chance to make an upset.