Help needed with upgrading bitcoin ABC
Yes, you need to upgrade.  You have version 0.16.2, and the 32MB block support was added in 0.17.0.  The latest release version is 0.17.2.

Your apt-get commands will only work if you originally installed bitcoin-abc from the apt package repository.  It sounds like you didn't.

You can check if you installed from a package at all with dpkg -l bitcoinabc.  If so then you can remove the package with dpkg -r bitcoinabc.  Otherwise you can figure out where the bitcoin-abc binaries are installed (using which or similar) and delete them manually.  Then install a new copy from scratch, either from the above-linked repository or any other way you choose.  (But this time make a note of what you did!)