Copyright works like this:
-you post video
-u go sleep
-u wake up, video muted.
-u are obligated to put shit music after, from their "150.000" epic music collection.
But yeah, like he Geo said, it either gets blocked, or muted or they make it unavailable on mobile device.
And no, remixes won't help, my remixes that arent EVEN on youtube get blocked because they find similarities within their Google Id system or something like that.