The DMCA process is law. Maven Central (like anyone else who hosts things) have to respond to valid takedown requests (which means taking down content long before any court case; even if a counter-notice is filed the content still has to be taken down temporarily) or else they'd become liable for infringement themselves. It's less common than on github or NPM, sure (which I suspect has more to do with the complexity of maven central's registration process than anything else), but it happens and any host on the scale of maven central needs a process in place for doing it.