Hello,

I suggest enabling the checkjobs option by default. This option was introduced
in bash 4.0 and causes bash to print a message if there are background jobs
before exiting an interactive shell. This is very handy if you forgot about
background jobs.
running jobs before exiting an interactive shell. If any jobs are running, this
causes the exit to be deferred until a second exit is attempted without an
intervening command. The shell always postpones exiting if any jobs are
stopped."

An implementation suggestion is to add the following two lines to
/etc/skel/.bashrc:

# list the status of any background jobs before exiting an interactive shell.
shopt -s checkjobs