The branch will likely be fine. I would leave the tree alone and let it grow.
Agreed. There are too many worries about their trees, whether msngoes or otherwise, of them being perfect specimens. Don't worry about them being perfect and don't worry about the imperfections. Mangoes are extremely hardy and resilient. The commonly heal ththemselves and even if one branch has a problem, in a few years you will never know it.
There is nothing wrong with monitoring your trees but bottom line, provide them with water, fertilizer and control pests only when truly needed and your tree will be happy and healthy and in a few years, reward you.