A kernel maintainer can completely ignore any submission with no repercussions even in principle. And they often do. In Firefox, in my era at least, a reviewer

A kernel maintainer can completely ignore any submission with no repercussions even in principle. And they often do. In Firefox, in my era at least, a reviewer who simply ignores a review request indefinitely was not doing their job and would get yelled at by someone --- me, if it came to my attention.