TORONTO - CHFI put a letter to its listeners on chfi.com today that says June 20th will be the final morning show for Jay & Billie. Such a warning is a bit of a departure for radio, since host changes are usually done without any listener warning at all - the DJs are just suddenly gone one day - so kudos to CHFI for that move.One could surmise CHFI might have learned a lesson from 2003 when it let long-time morning host Erin Davis go in June of that year to make room for Jay & Billie. One day she...