I of course have this same problem for a while now.
Why is it flagged as "needs more information"? It is pretty obvious
from the subject that /lib/udev/rules.d/56-hpmud_support.rules uses
SYSFS{}= "will be removed in a future udev version", so must be
switched to what has replaced it.
I've purged hplip for now, as I am tired of seeing this warning for a
long while.