Changing up2date to severn channel

[Justin Georgeson]

quoting Michael Schwendt:

> Well, using up2date to perform a distribution upgrade is not a
> supported update-path. But you can take a close look at the bottom of
> "up2date --help" and try what you'll find there. Have fun if it breaks
> your system into pieces.

Can someone from Red Hat clarify if the --upgrade-to-release option of up2date
is an officially supported way to do a live upgrade from one channel to another?
I recently noticed this option on my RH 9 box, and was under the impression I
could use it to 'upgrade' to any channel available (with the obvious exception
of RHEL channels for which I have no license).