hook_form_alter() implementations are still commented with a reference to a form builder that doesn't exist anymore

I was thinking to use the form ID returned from FormInterface::formID(), but I see that not all the form classes override that method.
The form ID is already be in the hook name, though. Since path_form_node_form_alter() is said to be an implementation of hook_form_BASE_FORM_ID_alter(), it should be already self-documented which base form the hook is altering. The problem is eventually how easily is to find the class implementing the form knowing the form ID.

It seems we can only use the form class. And to make it easier for users reading the documentation, the same comment should be used for the implementations of hook_form_FORM_ID_alter().
So, the comments for those hooks I was referring in my OP should be the following.

/**
 * Implements hook_form_BASE_FORM_ID_alter() for \Drupal\node\NodeForm.
 */

/**
 * Implements hook_form_FORM_ID_alter() for \Drupal\user\AccountForm.
 */

Whoops, I was producing the patch as per object. I will reroll it.

If the patch goes in, I guess the Drupal coding standards should be updated as well. Last time I read them, there was a part saying how to document hook implementations.

As secondary question, does the patch need to be done also for the 8.1.x branch, or such a change should be done only for the latest branch? I am not sure if this change should be considered equivalent of an API change, in some way.