I'm not sure. Is it an exception for this one page or this is a general rule that delete button should be on top? E.g. regarding https://bifrost.kolabsystems.com/T375653 What if the button will be in bottom-right corner?

In D1954#22264, @machniak wrote:

I'm not sure.

The main goal was to move it away from the submit button.
It should neither be on the same line as the submit button, nor in the form to make it clear that this is not an part of the actual form.

It being on the top is in line with the top "add" button being on the top of lists.

What if the button will be in bottom-right corner?

I like it a bit less but it would work on desktop. Less so on mobile UI. There the buttons would be close again.

Is it an exception for this one page or this is a general rule that delete button should be on top? E.g. regarding https://bifrost.kolabsystems.com/T375653

It is intended as a general pattern that would work for user accounts, user domains and so on.