Weight loss will not only reduce blood pressure, it will also help reduce blood sugar levels, excess wear of hip & knee joints, and give you more energy.
It is simple physics, the fatter you are, more blood has to be pumped through more blood vessels, which means the heart has to work harder, which requires higher pressure to pump all that excess blood. It is easier to propel a thin body versus fat body, which means increased energy.
Yes, that is all quite true.