As explained quite clearly on this article, hand (pointer) cursor should be limited to links on text and images.

The rule seems to be: for a button, there is no need to use a pointer cursor. for a text link, a pointer cursor should be used.

Currently, the underlying element is not altered: if you render a classic link as a button (<a> with class="btn") the cursor is still a hand cursor.
For example, in the documentation for the first button. For this button only, the cursor is a pointer.

Also note that the same is true for button elements rendered as links (<button> with class="btn-link"). The link should be rendered with a hand cursor. See this example on the doc.

A naïve implementation could be:

.btn-link { cursor: pointer; }
a.btn { cursor: default; }

If the solution is as simple as this, I can submit a PR.

Regards,