Comment 58 for bug 1895643

This is the verification work I did from a package management perspective, to verify correctness and consistency in a variety of scenarii:

1) In a fully up-to-date focal VM with enigmail, jsunit and tinyjsd installed, I enabled focal-proposed and updated:
    - from a terminal with `apt dist-upgrade`, debconf ncurses dialogs were displayed to notify of the removal of tinyjsd and jsunit from the archive
    - from the GUI (update-manager), debconf GTK dialogs were displayed

2) In a fully up-to-date groovy VM with enigmail installed, I enable groovy-proposed:
    - if jsunit and tinyjsd had been manually installed from focal-proposed (i.e. they are empty packages), they are not removed
    - if jsunit and tinyjsd had been manually installed from focal (release), they are removed with the upgrade

3) In a focal chroot without focal-updates, with enigmail, jsunit and tinyjsd installed, I hand-edited /etc/apt/sources.list to upgrade to groovy with groovy-updates and groovy-proposed and verified that jsunit and tinyjsd were being removed as expected.