I would be interested in a confirmation myself. But there are multiple reasons why people go for iEAD, spouses can go to work on iEAD, people can switch jobs based upon iEAD while waiting for their EAD to come through etc. Hence the demand of iEAD outside of the primary applicant continuing to work.
I really wish they would give EAD's that are valid as long as the 485 application is pending. It has been 3 months since I applied for my EAD and haven't received it as yet. But when I get it, it will be back dated to when I applied, effectively giving me less than 7 - 8 months on it, but since it takes 5 months to get a new EAD in any case, I might actually end up applying for a renewal before I get my EAD in hand. Freaking stupid asses! What can I say?