Both teams will have a chance to win. Bangladesh team was not in good condition in Pakistan a few days ago, they lost 3 matches in a row, Bangladesh is going to compete with Pakistan again, but due to the absence of Pakistan's top players, the squad may be a little weak or it may not be because some young talented players will be given a chance. If they can show their ability, Bangladesh will lose the match. It is not unreasonable to expect Pakistan to win 2-1 in 3 matches. Since both teams have a chance to win, it is better to bet on the team with the higher odds.
I will also agree with you and also say that the chances of Pakistan team losing this time series are high because Bangladesh will be playing it on their home ground and at the same time they have previously performed well against Sri Lanka in the T20 format and both of them will give extra confidence to Bangladesh team during the game. Which is enough to create extra pressure on Pakistan team.
Maybe if Bangladesh had lost the ODI series and Test series to Sri Lanka the way they lost the Sri Lankan series, I wouldn't have said this, but currently the Bangladesh team's confidence level is higher than Pakistan's, so they have a greater chance of winning.