Hi, just noticed this:

$ xdg-open https://fedoraproject.org
> egrep: warning: egrep is obsolescent; using grep -E

(more informative demo with a pun intended for a little bit of fun:
$ egrep egrep $(which xdg-open)
> egrep: warning: egrep is obsolescent; using grep -E
>             || ! echo "$1" | egrep -q '^[[:alpha:]][[:alpha:][:digit:]+\.\-]*:'; then
)

$ rpm -qf $(which grep xdg-open)
grep-3.8-1.fc38.x86_64
xdg-utils-1.1.3-12.fc37.noarch

See also the announcement
https://lists.gnu.org/archive/html/info-gnu/2022-09/msg00001.html:

>   The egrep and fgrep commands, which have been deprecated since
>   release 2.5.3 (2007), now warn that they are obsolescent and should
>   be replaced by grep -E and grep -F.

Also, for the sake of a more complete picture, note it looks like
Debian actually decided to revert the upstream change of raising those
compatibility warnings:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1019335

No particular opinion here, just following what's currently in Fedora
and assuming that Fedora is more prudent regarding the divergence
from upstream, which would favour adapting xdg-utils to this new
constrain than the other way around.

No upstream bug seems to exist for xdg-utils at this time.