on my guix installation (on an Ubuntu system but that detail should not
matter)

after running

%guix pull && guix package -u

these were printed:
----
...
New in this revision:
  ...
hint: Run `guix pull --news' to view the complete list of package changes.

hint: After setting `PATH', run `hash guix' to make sure your shell refers
to `/home/.../.config/guix/current/bin/guix'.

guix package: warning: Consider running 'guix pull' followed by
'guix package -u' to get up-to-date packages and security updates.

The following packages will be upgraded:
   glibc-locales 2.28 → 2.28
/gnu/store/acl2wxzzkkcjv74rlqswdf9p8pwddlmk-glibc-locales-2.28
   meson 0.50.0 → 0.50.0
/gnu/store/zc6r8b1rx3q7lqd8kvvpnm38ky925kmj-meson-0.50.0
   guile 2.2.4 → 2.2.4
/gnu/store/9alic3caqhay3h8mx4iihpmyj6ymqpcx-guile-2.2.4
   font-adobe-source-han-sans:cn 1.004 → 1.004
/gnu/store/zf59mg6g0afay9458aarh0rqcz852hhb-font-adobe-source-han-sans-1.004-cn
   fontconfig 2.13.1 → 2.13.1
/gnu/store/cnafj0dn09qzy23xnrrjsq5zcdj4739j-fontconfig-2.13.1
   epiphany 3.28.3.1 → 3.28.3.1
/gnu/store/n56bdjhqgq7a4a6ndqc3aymyrzvs12hl-epiphany-3.28.3.1
   gnome-terminal 3.28.2 → 3.28.2
/gnu/store/r6i61wji0qmv9fqdyk65kx73nzxw8v80-gnome-terminal-3.28.2

nothing to be done
----
Now there seems nothing to be done during the guix package -u step so these
messages
glibc-locales 2.28 → 2.28...
were confusing and probably not necessary?