I doubt this, Reddit has had their own app for years now and every Reddit mobile page on the web nags you to download it

Literal brothels run Instagram, Facebook and Twitter accounts and the content definitely isn't safe for work.

So does Tumblr, the way the article put it was that any site with user generated content would inevitably have awful things posted that get missed and might get randomly discovered by the randomly assigned reviewer's search and judge by the random reviewer's standards loosely based on some hidden guideline.

I don't know about these statistics, but Tumblr is definitely NSFW-only, that was the whole deal back in 2018 that got everyone angry at them. There were some other minor differences about defaults suggested in the article as well, it didn't seem especially conspiratorial.

Of course, tolerating twitter due to its size and ability to single handedly generate PR doesn't seem that conspiratorial to me. I'd be kind of surprised if that wasn't a big factor in double and quadruple checking the results before taking action instead of the reverse.

Twitter doesn't.