I don't think specifics and details mean that we're getting the whole story, at all. I am sure Harry and his mates has a side to tell.
Chandauka is undoubtedly being selective to make her case BUT I would agree with you that the specificity is very likely to mean that the anecdotes she is picking are backed up by documentary evidence.
If Chandauka has email trails which show that big donors pulled out because of Harry's perceived toxicity, or which show that Harry tried to turn Sentebale into a commercial enterprise by involving Netflix, or which show that Meghan was able to attempt to interfere in the charity and bend it in the service of her PR machine...well, than Harry is cooked, basically, as far as charity patronage goes.
Cooked, piping hot and sprinkled with dead flowers. It's over, fella.
That would be very sad for him. But crucially it shows what a wise woman the Queen was, despite attempts by antimonarchists through the years to portray her as a brainless, emotionless cipher. She KNEW this shit wouldn't work.
This is why in my culture we're taught to have respect for our elders. Especially elder women. They KNOW shit.