I’m pretty sure it was just an advertising change. The structure appeared to be sound.
I drive past that set of billboards 4-5 times a week and never saw any vandalism towards it (paintballs, etc). Our local whiny News-Press columnists and bloggers bemoan it as divisive, but I love it.
I would love to see “Where’s the Birth Certificate?” billboards all across America, on roads, car bumpers, and as lawn signs. ( One can dream.)