Add comment to occupy removed protobuf nodes

              I think we should add comment to occupy this position of `16` @dmitrybugakov @alamb @Omega359

_Originally posted by @liukun4515 in https://github.com/apache/datafusion/pull/10202#discussion_r1577553331_
            