I think I was the first to comment in this thread on the whole book which I had just read, having borrowed from friends. What I wrote at the time about Harry supposedly saying that to his grandmother is below. And the thing about Prince Philip's supposed remark first appeared in a tabloid weeks before.
My verdict on this biography . What you might expect from Lady Colin judging by her past writings. A scattering of unnamed sources, 'a Prince', 'a cousin of the royals', 'a courtier' etc, along with what appears to be an all encompassing trawl of tabloid articles, social media outlets including Tumblr, and the opinion of the author, almost invariably unflattering to both Meghan and Harry.
A sample. She states that Harry in asking formal permission to marry, told his grandmother the Queen that he intended to marry Meghan 'And if you don't like it you'll just have to suck it up'. Yes, that sounds exactly like how Harry would speak to the grandmother he reveres and respects!
Lady C further asserts that 'a Prince' was present at this meeting and told her that Harry informed his grandparents that 'they would be accused of racism if they did not agree to the marriage!'
Apparently that threat worked !! as a few pages later Lady C states that 'the Queen and Prince Charles were particularly delighted with her virtues, not the least of which was her colour'. Source, same unnamed Prince. (It is one of Lady C's claims, long asserted on social media sites, that the BRF 'wished to appear diverse' and that is mainly why the Sussex marriage was allowed.)