Hello, Sometimes when we look at our friends list, we see that some friends have removed us. I would like to have some kind of notification when a friend removes me so that I may send them a message and ask them why they would remove me as we were friends and there is no reason to remove me. These people do not have 200 friends as I know them and they do not have very many friends and so I would like to know immediately when they remove me so that I can ask them why they removed me. Thank you.

I feel like that would lead to harassment. If they remove you there’s probably a reason, like they just got tired or something, diddn’t feel safe etc. you best approach this sensitively and sometimes not directly. And, to me, people should have the choice to walk away from anything they don’t enjoy. Notifying kind of just suggests that they did something wrong from an ethical point of view. Friendships are not a contract, legal binding or anything. Whatever your friendship was based on, it has ambiguous value that varies between people.
Consider inboxing them, if they’ve not blocked you or go through someone else.
Just my view

Agree with Emerald. More to that, facebook neither notifies you when a friend removes you. Guess there's a good reason for it.