When the savedconfig USE flag is enabled And /etc/portage/savedconfig/sys-kernel/ does not exist or linux-firmware was not installed before Then the /etc/portage/savedconfig/sys-kernel/linux-firmware file should be installed without trailing ${PV}. Presently it gets installed like "linux-firmware-20200421" regardless if savedconfig is enabled or not. If users who want savedconfig forget to rename (remove ${PV}) then next upgrade removes their configured config.
Not a package bug. That's how the eclass works. You are basically asking to change behavior of that eclass.
For the relevant use case I noted down in the wiki article to remove "-{PV}". https://wiki.gentoo.org/wiki/Iwlwifi#Optional:_savedconfig RESOLVED OBSOLETE