Oooh, so cute, you are now feeling great izzat by stealing credit of Hindi movie industry and somehow inferring Bengalis understand urdu since they understand hindi. Doesn't it hurt your uzzat that you need to borrow the credit of your enemy to somehow feel good about yourself?
All BD people is probably a bit o stretch, I can understand hindi say almost 80% but can't speak. Many BD people are like that. But no BD people can read or write hindi or urdu except some people (maybe academics) who learned it for one reason or the other.
Also bd people understand the vernacular urdu because it is same as hindi. They won't understand proper urdu, not even 30%. I have tried to watch on YouTube urdu news a few times, gave up because I don't even understand 30% of it.