org-agenda-skip-function not honored by 'tags-tree' custom agenda view

[João O'Neill Cortes]

Tested with org-mode version 9.7-pre.
Looking at section 'A.7 Special Agenda Views' of the info org-manual.

It is stated that 'tags-tree' searches can set
'org-agenda-skip-function' to some function that decides on the
visibilty of each match.  For what I gathered, by setting up something
like this,

     (org-add-agenda-custom-command
      '("b" tags-tree "some-tag"
        ((org-agenda-skip-function 'my-skip-function)
         ))) 

, and then calling 'org-agenda' and selecting the 'b' entry.

It does not work, and 'my-skip-function' never fires after the request
is made. It works for some types of special agenda views though, like
'todo', but not with 'tags-tree'.

Is this a bug?