I agree with you Charles. But...
1 - If IBM publishes the 'migration' at
then that must be another officially supported path also.
2 - Not everyone has multi lpar or multi box environments to test.
Granted, this person will have a new system which could be an ideal test
environment. Perhaps we don't know all the details, like is the new
system really functional without taking some critical hardware out of the
old one and putting it into the new one?