Re: Questions after doing update and upgrade on Stretch
As for reason why old one is not removed, it is because Debian keeps not
just newly installed kernel, but also one previously installed. One
before that was removed by apt-get autoremove.
Unless different desktops have different autoremove behavior in my recent
experience kernels can only be removed manually. If you get a current
today's image of 8.8 and update/upgrade, then switch to testing and upd/upg,
then unstable and upd/upg and autoremove as many times as you like,
you will end up with 3 kernels as a choice to boot unstable from.
I think in the past it did not work this way.