Comment 13 for bug 2063899

$ apt-cache policy ubuntustudio-installer
ubuntustudio-installer:
  Installed: 1.18.2
  Candidate: 1.18.2
  Version table:
 *** 1.18.2 100
        100 http://us.archive.ubuntu.com/ubuntu noble-proposed/universe amd64 Packages
        100 http://us.archive.ubuntu.com/ubuntu noble-proposed/universe i386 Packages
        100 /var/lib/dpkg/status
     1.18 500
        500 http://us.archive.ubuntu.com/ubuntu noble/universe amd64 Packages
        500 http://us.archive.ubuntu.com/ubuntu noble/universe i386 Packages

* Created new user
* Signed-in as new user
* Ubuntu Studio Audio Configuration launched, prompted for reboot
* Signed-in as new user, launched Ardour
* No complaints from Ardour

This does appear to be fixed and will properly configure for current users.