Note that the rooms you are referencing are a special case and are very discounted compared to their "normal" standard room. When I made my reservations, the hotel was very upfront that those "small" rooms were very discounted and treated differently. If you want to possibly get an elite upgrade, then reserve a standard room. I didn't have any issues given how upfront the hotel was with those "special" small rooms or with the price they offered them at (I was attending a conference on my own dime and getting one of those rooms was a heaven send given how low the rate was compared to every other hotel in that area.)

So to me, the Ren Pere Marquette's statement about upgrades for just those special rooms is very different than the OP's situation where the NO Marriott said they don't upgrade any elites at all. But just like your situation at the Ren Pere, there may be more to the NO Marriott's upgrade statement than we know at the moment.