I think it's easy to see that a lot of things went wrong regarding Meghan's introduction to the Royal Family. I don't know much about the power behind the Royal Rota, and what it would take to change it (possibly the involvement of Parliament, since the issue includes both the press and the royals?), but it has been royal policy (official or unofficial) for decades to ignore unfavorable press. And often, when they have broken that policy, it's backfired, thus reinforcing the policy of disengagement all over again. Camilla went through a horrendous time, not too long ago. So yes, I can easily see the palace not recognizing racist dogwhistles because a lot of the stories brought up (such as Meghan during her pregnancy, or the stupid avocado thing) aren't overtly about race, and can just seem like the sexist nitpicking that all the royal women have endured. The one thing I do think the Queen should have publicly responded to was the overtly racist attack on Archie.
I still think the timeline of Meghan's royal life was very short, without a whole lot of wiggle room for making adjustments and trying to make it work for all involved. The Queen did seem to take an active interest in Meghan's royal debut, and Meghan herself did seem eager to jump in full-steam ahead and shake things up. In hindsight, that was rather naive (and maybe even a little presumptuous) of her. And while Kate's long pre-engagement relationship with William may seem unnecessary to people, it did give her years of observing and learning that Meghan didn't have. She probably understood more how being royal isn't really a job, as much as a lifestyle. And I don't think Meghan or Harry really accepted that.
The one thing that still strikes me as odd is the big People magazine article with Meghan's friends defending her. Sure, maybe I'll buy that none of them mentioned anything to Meghan, and she had no idea. Whether she knew or not really doesn't mean much to me. What I don't get is airing everything in an American publication, when the American tabloids were much more supportive of Meghan to begin with and the barrage of criticism hadn't really gotten much coverage here, unless you were looking for Brit media. And I do wonder if that counterattack further soured relations in England.