It's probably counting things like the X-Men movies, Spider-Man movies, Blade, Fantastic Four, etc.. Things that might be/get tied into the MCU, but aren't really a part of it.

As for the DCAMU, yeah, it's more adult. Some of the movies were too adult for me - one of the things I am picky about. It's the reason I don't like the Suicide Squad (I really like the concept, but the crude humor isn't for me.) The movies are also edgier than the MCU, but I can't say whether they're edgier than the live action DCEU; I haven't watched most of them, but I know they tend to be darker to a fault.