I've added some bold parts to your quote above.
I somewhat addressed your questions in the post above, but to add a bit more. "Taking offense" is a subjective process, based upon interpretation and identification. Subjectivity changes. Our frameworks of interpretation change; what we identify with changes. We are, as individuals and cultures, constantly in flux.
OA is a cultural artifact. It is a moment in time. By changing or removing it, we artificially alter or bury the past, and we diminish our capacity to see where we've been and thus consciously determine where we might go.
If people are offended by it, that is their right -- just as it is their right to voice their offense. But it is my opinion that their underlying concerns are better addressed by suggesting a path forward, not negating the past. "OK, that was 35 years ago. What might an Asian-themed D&D book look like now? What have we learned?"
To take a more extreme case, Andrew Jackson's "Indian Removal Act" was deeply offensive by almost any measure of interpretation. But should we, ah, remove it from the record? It is a very important historical document that tells us how the POTUS--and many people--viewed the native people of North America. OA's level of offensiveness is obviously miniscule by comparison, and of course it differs in that it is a privately owned property. But within the context of D&D, doesn't the same logic apply? Don't we need our cultural and historical artifacts to help us redefine ourselves, again and again?