It should keep those connections. The file storing those connections is not stored in the installation folder, so as long as you don't clear out your appdata(?) folder, they will still exist.
Having said that, just to be sure, open Tools > FME Options > Database Connections from the menubar in Workbench. Select all of the database connections and then right-click on them. Now select Export. Then you'll have a backup copy of the connections that you can re-import into the new FME installation if the need arises.
Hi Mark,
Thank you for the clarification. I will opt for the option of importing all my connections in a file in xml format before migrating to the 2020 version.
Regards,