The police are not abusing law. The bots that do the automatic take-downs are abusing the law.

This is not State censorship, because the police are not censoring the videos. People still get to record them, and still get to share them. If they can't be bothered to post somewhere other than Instagram (which is abusing their rights), then the failure to share is on the people doing the posting.

There's nothing stopping the people who recorded the videos from sending them to the news media. The recordings are still getting made.

They're just being removed by some bot from the Instagram feeds. Shame on Instagram.