I worked on Facebook copyright claims etc for two years, which uses the same systems as the reports and support cases at FB.

I can't say it's the case for OPs case specifically, but I absolutely saw code that automatically closed tickets in a specific queue after a random(15-75) minutes to avoid being consistent with the close time so it wouldn't look too suspicious or automated to users.

>It wouldn't take 15 minutes to investigate.

If they actually took the effort to investigate as needed? It would take them even more.

Expecting them to actually sit and watch the video and understand meme/joke talk (or take you at face value when you say it's fine)? That's, like, crazy talk.

Whatever size the team is, they have millions of flagged messages to go through every day, and hundreds of thousands of appeals. If most of that wasn't automated or done as quickly and summarily as possible, they'd never do it.

Could very well be! But also let's not forget this type of task is outsourced to external companies with employees spread around the world. To understand OP's comment was a joke would require some sort of internet culture which we just can't be sure every employee on these companies has.