I believe a change to the last line of org--file-default-apps introduced 
in 9.5.3 is a bug.  For example, the change prevents shell scripts from 
being recognized correctly, since the mailcap logic in org-file-apps-gnu 
is no longer included in org--file-default-apps.

Best wishes,
-Craig Stcr1


org.el 9.5.2

    (defun org--file-default-apps ()
       "Return the default applications for this operating system."
       (pcase system-type
         (`darwin org-file-apps-macos)
         (`windows-nt org-file-apps-windowsnt)
         ('org-file-apps-gnu)))


org.el 9.5.3

    (defun org--file-default-apps ()
       "Return the default applications for this operating system."
       (pcase system-type
         (`darwin org-file-apps-macos)
         (`windows-nt org-file-apps-windowsnt)
         (_ org-file-apps-gnu)))


diff

    8701c8700
    <     ('org-file-apps-gnu)))
    ---
     >     (_ org-file-apps-gnu)))