Like I wrote in the initial comment, I cannot come up with a case where it would be useful for "install" to actually "remove" some (often, apparently unrelated) packages.
For "upgrade", I can somehow see how at least sometimes this would not be surprising (if you have an auto-installed package which used to be Depends: but which was demoted to Recommends: maybe?) -- aptitude: install --without-recommends removes packages https://launchpad.net/bugs/56742 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
