I had not seen this before, but since LRO is supposed to reimage the Apollo sites, I thought I would bring up the shadow casting of the flags.
I had seen that the LRO-ASU presentation that the Apollo 17 site had the flag still there, but it had been shown as a dot. Yet, if you examine the images at various Sun angles, you can see the shadow cast by the flag on the flag pole. Obviously when the Sun is directly overhead, you will see a dot if the flag is “up”. But for other Sun angles, the area of the shadow changes as it is cast over more terrain. Seeing the movement over a range of Sun angles is the best proof it is a flag on a pole.
This is an animated GIF showing key Apollo 17 site images.
This image shows the first frame and where the starting flag shadow is.
Animated gif with flag shadow pointer guide.
Both Apollo 12, 16 have some similar shadow casting showing that the pole is still up and a flag is attached.
Apollo 15 doesn’t have an obvious shadow cast although it is in a position to be able to cast shadows that can be seen. So it's pole or the flag fabric might have been knocked down.
Apollo 14 has the flag in a bad location such that shadow casting at various sun angles is not apparent.