Virginia has been trying to make this happen for a decade. Their first efforts to rescind failed after backlash. Then they stumbled on the HOT lane as a way to achieve their goal, which has worked really well.
Now, as the number of us who have the old grandfathered tags has dwindled, our political power has fallen too. With the last segment of I395 transitioning to HOT lanes in the next month or so, there aren't many roads that remain HOV.
It appears that almost all PHEV and BEVs meet the federal standard that the state cannot repeal, so if you have a grandfathered plate, a PHEV or BEV, and use one of the few remaining HOV roads (Dulles toll road, I66 outside the beltway) you should still be able to use the HOV. If you do, I would recommend having all documentation in the car that you still comply.