Recent can be subjective, you can say even 5 days as recent however since world cup to world cup 4 years is a cycle which even Cricinfo considers in its stats so counting from last world cup , it hasn't been good readings for Pakistan. Taking a time span of 25 years is too long however as you might not have been even born when that time span started.
Out of those 4 ODIs, 3 were against a completely different Pakistan outfit at home right after CWC'2015. We pretty have much sorted out our team after T20WC 2016, at least we are good enough to beat minnows like you in a bilateral series 10/10 now. Anything can happen in tournaments, it has been 2-1 in favour of Bangladesh in recent times, but you should remember than both the games that Ban won were pretty close, while the game in WT20 was a lifetime lesson for Bangladesh.
The only thing Bangladesh Cricket has ever won is a the claim to the "realm of delusion". As far as this game is concerned, Pakistan start favourites, but anything can happen in a one-off game. Even Kenya has the ability to beat us once or twice, but that doesn't make them "world-beaters".
Your guys are lucky to have the likes of Shakib,Tamim, Mahmudullah, Mushfiq. Mashrafe, once they depart, the dearth in Ban will be clearly evident. None of your so-called young talents step up, and when these 4 guys are gone, it's going to be difficult.
I sincerely hope Ban are able to find some good young talent, honestly want you guys to succeed. The thing though about Bangladeshi fans is that they lack sportsman spirit.
If you don't know how good you actually are, then I feel that chances of improvement are pretty slim.