I only ask because my sister told me they were mindless fun and said I should add them to my ever expanding queue of books to read. I heard about the disney plus show and I find the author to be annoying for going after people who wanted to see the characters as described in the book. I could honestly respect you if you were to say "They offered me a ton of money to make the usual trendy/modern audience changes to my book" instead of that he wanted to be more inclusive. If he felt that way then he needs to write a fantasy about a black girl or he should've made the character black to begin with. Not sure how many black kids were reading Percy Jackson (I could be wrong but I'd guess not as many as other groups), but I'm sure the ones who read them enjoyed it for what it was.
I know with ESG and stuff this is currently impossible but you could fix at least some problems in entertainment by simply saying that for whatever reasons certain hobbies/genres don't appeal to certain groups in large numbers and running off the core fanbase with the moronic notion that you will get some mythical new audience is absurd.
Exhibit A: Star Wars. I'm strictly pre-Disney star wars at this point. It would have to take new leadership at disney admitting to their mistakes and continuing EU stuff in it's own separate continuity because you had a loyal fanbase that you pissed off immediately. Could've thrown them a bone with some animated adaptations or finishing Sword of the Jedi at least. Comic books, video games, etc. Better yet, if a lot of white males enjoy a hobby, there is nothing wrong. Tolkien wrote LOTR for the British people, but anyone can read it. I am free to read and watch Japanese content. If you want to appeal to certain audiences, then make something you think will do the trick. Granted, it is much easier to bastardize or crap on whatever someone else has made (Wheel of Time).
Ok, sorry for yet another rant.
He give any reason why he added it?
Nope.