I can understand the reasoning, and I can certainly appreciate if someone has trouble adjusting due to a sense of things not being consistent. But what I think is a bit silly, is instead of people framing this as their personal preference, it is framed as a blanket rule (i.e. movies and shows ought not change the race of a character). When I think that is a judgement call that really needs to be weighed form production to production. Like I said, I wouldn't advise changing race of a character mid trilogy, but if it's a reboot or just a really long series with a tradition of changing actors (like James Bond), I find it being open to different physical types to play the role can be both refreshing to the franchise and truly allow for the best actor for that role to be selected. Case by case obviously. In this instance, there is just nothing about Hermione in particular that suggests to me she needs to be white. If they had altered the character midway through the movie series, that would have been an issue for. But this is a completely new production. Having someone play the role who looks different form the original actor in the movie isn't going to phase me.