I believe EEO is an offer and Marriott Concierge said "cannot be combined with any other offer". But anyway if you read through that whole thread you'll see that this was referring to EEOs also. Quote from post 46 there:

"Again, this promotion cannot be combined with any other offer, discount coupon, sale promotion, prior purchase or purchase of a gift certificate. EEOs are special offers and cannot be used in conjunction with the RejuvaNATION promotion. I apologize for the misinformation you, and others, were provided. If a hotel accepts the combination of the RejuvaNATION rate and any other offer, discount coupon, sale promotion, or prior purchase or purchase of a gift certificate, it is a goodwill gesture and not a requirement for them to do so.

Best regards,

Drew"

Don't get me wrong I believe they should be valid especially considering my point in that thread, that at many hotels I have no choice but to book the Global Rate rate (if I don't want a golf package or a spa package and those wouldn't work for EEos anyway) and it's not right (and a little silly) that I can't book a hotel for the next few weeks and not be able to use an EEO. But you can read through the whole thread for all the points and counterpoints.