Whether your video gets flagged (it will) vs muted vs removed / blocked is a function of who owns the copyright material itself.
Many labels have standing agreements with youtube that if a video has copyrighted material they own, the video may just be flagged, or it may only be blocked to certain markets (depending on international copyright agreements...so, for example, Germany gets blocked a LOT!).
However, they'll leave the video up and running, and youtube will pay a portion of any click ad revenue generated to the owner of the copyright, as well as use the content matching system to pitch the song/single next to the title.
This is a win/win for youtube and the content holder, because they both make money (or the potential to make money) off of what is basically freely provided content that they didn't have to pay to produce.
Some labels or individual content holders (and yes, there are people who squat on copyrights just like they squat on trademarks) don't feel this way, and those are generally the ones you'll see taken down or muted.
Since there is no public list of what content is "blacklisted" or not available from youtube, it's really hard to figure out if your video is going to get disciplinary action.
However...once you start to monetize your videos (i.e., become a youtube partner), the metrics change dramatically. This is because a third party (you) is now involved in the transaction, and getting a piece of the monetary pie.
There is a caveat under fair use, however. So, if you were say, making a video about Spaceship Earth, and you used the SSE music loop in the background, it could be qualified as "fair use". The line is very blurred on this right now, and generally overlooked for popular youtubers...with one section that has been hit pretty hard at the moment.
Game reviewers.
This isn't the first time this has come up, and it's why many high profile early youtube review shows left to join Doug Walker (Nostalgia Critic) and That Guy With The Glasses, or have moved to Blip, or just disappeared completely.
Your best bet, if you want to use Disney songs and loops, is to reach out to them and see if they are willing to grant you limited rights to use their property. Good luck there though. May just be better, as a fledgling, to give it a shot and see what gets flagged and deal with it like that.
