I am mixed race and these days are usually fine in my book.
They need use some of the more exciting, colourful parts of our culture to spark the kids interests. They are usually the bits we are stereotyped for.
You ask what you should do as a white woman? How about actually find out more about what they are teaching. Make an informed decision. If you don't feel you have enough knowledge to make an informed decision, speak to people who do.
They have involved local people from the communities they are celebrating. So chances are the snippet you and this man saw, is not enough to say 'its cultural appropriation'.
Our school has had interest weeks on all 3 places my family are from and local people did from those backgrounds got involved. They were happy to be involved, helped with the whole weeks learning points, suggested additions or advised which things that weren't important and to remove. And also some stuff that's very popular from the cultures, that is stuff that kids recognise.
If people from that community have been involved and happy, then it's appreciation. Do you not think the people who have helped them, wouldn't have had this cross their mind? Wondering if the school are doing something good or something inappropriate before getting involved.
That parent could be just wrong, not asked what the schools aims were or know the detail. Just because we aren't white, doesn't mean we are always correct. And even if after learning the detail, if he still thinks it's appropriation. That's just ones person's opinion. The rest of the people living close by, with he cultural background may not agree with him.
Nothing you have said here, says cultural appropriation. It's say cultural celebration in a way that gets kids excited and engaged.