I don't understand why it needs to be so political. IMO, yes, he shouldn't remove it but there are reasonable alternatives such as another maintainer setting up a network-manager-sysvinit package that just includes the script (like git-daemon-sysvinit) or even an entirely new package such as network-manager-sysv containing the same files and the script. Then everyone can be happy - the said maintainer can live on without sysv and those that want sysv can live on with their specialized package.