I dont get why all discussions about US boils down to getting a bunch of F16s? There is much more to be gained from US in terms of military equipments, even if they decline selling us F-16s. Heck, having a military alliance with them will even open European/NATO platforms for us. We can then look at countries like France, Germany & Japan for arms, given we already have good relations with UK. Turkish options will be super available as well as Gripen will become up for grabs. We can easily negotiate a refusal for F-16s with permission to buy Gripen.
The timing of this proposal from US comes at a time when its too obvious. They are well aware that we are totally isolated regarding the Rohingya issue and that this did not leave a good impression about the Chinese within the political higher-ups and normal masses, further reinforced by Momen's meeting with Pompey and us looking for Turkish/European platforms. When such times strike, you learn who your true allies are.
Not to mention, US does have its own interests in mind. Nothing is free. What we now have to do is understand what they want in return and does that in any case hamper our stable economic growth and development goals. Because, notwithstanding all the hate, US is still the largest and the most influential economy on the planet. A few good deals and you could see US companies coming to Bangladesh with large investments, again a win-win.
You also need to have a long term thought-process. According to a news report few months ago, Bangladesh is now the 4th largest country from where graduate students go to study in US. These students mostly stay back and go to work in academic and industrial domain. Couple of generations down, expect to see few Bangladeshis in the US political arena too, just like in UK. All these will have benefits for us and having a foundation in place like such deals/agreements would help us leverage those benefits.
So there are perks to be had and this would be an opportunity too hard to ignore.