Originally Posted by number_6
Yes, in 2 ways: they may not have a special meal in the higher class, and skip you for another candidate to op-up. And, more importantly, they may not have an extra regular meal in the lower class -- for the person who will be taking your freed seat -- and not op-up you even if you insist that you are happy to have no food for yourself. In general, special meal = no automatic opup. Of course human intervention can still get you an opup, but special meal cuts your chances by an order of magnitude.
It would depend on the relationship between the two classes, though, I would think.
As I understand it, WT+ has the same service (and thus the same meals) as WT (it's just a somewhat nicer seat, basically -- I think of it roughly as a cabin full of exit row equivalent seats), so an upgrade to WT+ from WT (or a downgrade the other way) would mean zilch to a special meal except for the keeping track of which seat it needs to be delivered to, no?