crontab uses a hardcoded reference to /bin/vi as editor but
vi is /usr/bin/vi with the current VIM package.
krusty 531 bash$ ls -al /bin/vi
-rwxr-xr-x 1 root root 552808 Mar 25 17:40 /bin/vi*
krusty 532 bash$ rpm -qf /bin/vi
A quick "strings -a /usr/bin/crontab" gives one hope that
EDITOR/VISUAL are honored also.