I
noticed that in recent weekly builds, many firmware packages are
missing from the live desktop images. I believe that the problem is in
this file
https://salsa.debian.org/live-team/live-build/-/blob/master/functions/firmwarelists.sh.
Its logic depends on firmware being in /lib/firmware, however, firmware
has moved as a part of the usr transition to /usr/lib/firmware. I
didn't have a chance to test, however, it seems likely that updating
this path to /usr/lib/firmware in that file would get detection for
firmware packages working again.