The point is that, when discussing racism or prejudice in the workplace, all you need to do is stress that the rules have to be obeyed. End of. Like I did as a union rep.
I once led such a session, for managers, and I set it up like this:
1. These are the rules - read, mark, learn and inwardly digest.
2. Follow the rules to the letter in all circumstances.
3. If you break the rules, I will come down on you like a thousand kilos of building materials!
I went through a couple of case studies, to show how the rules applied in different situations. This was the only discussion I allowed.
Afterwards, a Black manager approached me and said "That won't stop people being racist." I replied "That wasn't what it was for. It was to stop them acting in racist ways. I don't care what they think, only what they do!"
You can spend your life trying to change peoples' minds, and end up depressed, or you can control the way they act, and succeed.
The vast majority of people are as dim as a Toc-H lamp. You can't change their minds because they don't have any. You can, by means of a small carrot and a big stick, change the way they behave, and that's what is required.
As regards matters such as Ramadan, etc, being Black, LGBQT+, disabled, etc are things about which people have no choice, so should not be factors in their sucess, etc. Religion is a lifestyle choice, and as such, is not a matter upon which employers or the law should make allowances, since it can be changed at will.