Keep looking forward, eventually the CBB will need to be replaced.The FSK bridge was a toll bridge, I assume the replacement will be as well.
I don't know what they will gain by making it higher- the FSK had 185 feet of clearance, and the Chesapeake Bay Bridge is something like 182 feet. Any ship that goes to Baltimore has to first clear the Chesapeake Bay Bridge, so....
I don't know what the benefit/cost is for raising the bridge(s) is.
I'm sure the number crunchers are hard at work planning things out.