Do all the VDDIO pins need power in on a chip?
Short answer is yes they should all be connected.

Two reasons spring immediately to mind.


Current supply to the IO on the chip the IOs and power are connected by thin aluminum traces. If these do not blow immediately if trying to supply to much current there is a phenomena known as electro migration which will tend to make a thin point in the track thiner and lead to failure later. ie a reliability hazard.
ESD protection circuits on the IO rely on the voltage at the IO pads being firmly controlled to prevent ESD damage and latchup. Each IO needs a voltage source reasonably close to it electricaly to achieve this.