I think you're missing the point of why "oriental" is offensive.
I think you're misinterpreting which side of the discussion I happen to be on. I was listing common arguments that are used to justify usage of the word "oriental", not actually supporting them. That's why they are in quotes.
The fact that "Asian" and "Orient" are synonyms is irrelevant. "Negro" and "Black" are synonyms too, but there are subtler shades of meaning that the words have gathered over the years that go beyond their original definitions.
I really don't get why people want to argue this. How important is it to you that the word "Oriental" be in the title? Why is that important? Because it was in the title of an RPG supplement that you played as a kid? Who cares? Not all media is an attempt to recreate your youth.
Or maybe it's because you just are a stickler for precise dictionary definitions of words. I doubt that, though. Plenty of words get used publicly in ways other than initially intended and I don't see massive forum posts about those. It seems like people are more likely to be pedantic about precise meanings of words when those words are offensive to others. "Oh no sir. I was merely calling you a bundle of sticks. Don't be such a female dog about it."*
Anyway. I already mentioned that I don't want to argue about it anymore. It's really pointless. Some Asian people don't like the word "Oriental" because it is exotifying to them. People don't like being exotified. Therefore it would be a bad business practice to make that the title of a supplement.
The earlier comparison to "Out of the Abyss" is silly. WotC doesn't have to worry about offending demons because demons aren't real. They may offend fringe groups like some extreme religious people, but that is unavoidable. The fringe groups are going to be offended at something no matter what. But the difference is that "Out of the Abyss" doesn't use terms that categorize actual people based on how or where they were born. That should be obvious.
Most of all, it really doesn't matter. I highly doubt that WotC is going to put out a supplement with the word "Oriental" on the cover. End of story. Any whining that the case should be otherwise is pointless. "Oriental Adventures" isn't even a great title. Something more evocative will probably be used. I mean "Out of the Abyss" could have been called "Underdark Adventures with Demons Too", but they went with a better title.
*Note that the preceding words were in quotes. That is because they are the words of a hypothetical person who's argument I would disagree with and not my actual thoughts on the subject.