If we limit the term 'op-up' as strictly complimentary movement of passengers from one cabin/class to another, then E- to E+ will not be considered as an op-up.

However, in my book, UA's elites and others who get free access to E+ when flying economy, already get complimentary upgrade. UA's E+ seats clearly offer more space and comfort, and one of the reasons I will only fly UA (as much as possible) when flying domestically and internationally. It's an op-up ^