Bangladesh and China are not friends,but also don't have to be enemies, Bangladesh is surrounded by India, Myanmar and China, the country can rely on the west and Japan but they are far away and are declining, it's not smart to make everyone in Bangladesh's neighborhood an enemy.
Yes Myanmar is very important to China , China has huge investments in Myanmar and China won't allow western influence to infiltrate into China's backyard, this policy won't change cause it's a matter of national security, don't expect any nations to hurt themselves in order to help others.
It's unwise for Bangladesh to jump on the western China bashing wagon and try to hurt China. China and west share a lot of common interests economically and politically, the relationship can be improved anytime, the west only wants Bangladesh to serve as their anti China canon fodder, if Bangladesh chooses to walk down the anti China path, it will only end up hurting itself.