Nope. BD Navy will be strong enough to stop blockade in Bay of Bengal.
PLAN will take care of any attempt to interfere with BD merchant shipping in the rest of IOR.
Take about false bravado. In 1971 Indian navy lighted up the Karachi harbor with relative ease.
India has multiple ways of shutting down Bangladeshi ports
aerial strikes from shored based aircraft
missile strikes from corvettes
submarine warfare
mines
Bangladesh navy will be gone in 48 hours. Bangladesh navy has no minesweepers or ASW aircraft. As far as PLAN saving you West Pakistani army in 1971 was waiting for China to bail them out too.
Bangaldeshi leaders are sane. Even the ones that spout anti-Indian rhetoric know their limitations of their country. Most Indians are happy to see Bangladeshis happy and content in their own country.
I hear your complaints on the Farakka barrage and flood control. I do not know of any solutions that will make everyone happy. The solutions are not cheap.