In that setup entr only watches files that existed when systemd service was first started. So new files won't trigger backup. Something like this should work:
while true; do find $ORG_DIR | entr -d -r rclone sync -v $ORG_DIR $REMOTE:org; done
while true; do find $ORG_DIR | entr -d -r rclone sync -v $ORG_DIR $REMOTE:org; done
I've never used it myself, but I know systemd has file watching built in. I think using `PathModified=/path/to/org` would also eliminate the need for entr [1].
[1] https://www.freedesktop.org/software/systemd/man/systemd.pat...
The systemd solution may be even better, though it seems there is no way to ignore changes in temporary files that emacs likes to create.