It usually depends on Content-ID system
Basically labels/producers use this youtube's system to find any video on youtube using their music,whenever a person uploads the video this system detects it and it does what the original owner has decided.
The laber/producer can either choose to block the video,in this case a copyright strike is given and it affects the channel standing OR the owner can choose to display ads on that video so all the revenue from that video goes to the owner and in this case there's no copyright strike and nothing happens to your channel's standing just you can't monetize the video ,basically you can't make money on that video.The owner has to decide it when he puts his content into this system so the system automatically detects the content anywhere and whenever it's uploaded so the owner doesn't have to search all the times and do this stuff