Originally Posted by
JonNYC
That's incorrect, SpammersAreScum has it right.
JonNYC, could you please clarify what part of it is incorrect? SWU (or miles+copay) can be used by anyone, is not a direct status benefit, and may be unrelated to status -- in a way that is not true of 500-mile upgrades. Is the waitlist position advantage the crucial factor in your assessment? In that case at least anything cleared from published C inventory should be okay.
I have encountered this issue and have been consistently allowed by AA to switch numbers after clearance of a waitlisted SWU to credit AS (but not for 500-mile upgrades). My biggest problem was getting the per-segment FF number to work, so I could credit the outbound as desired before clearing the return -- usually it required cleanup (moving credit from AA to AS) afterward.