Obviously it isn't in everyone's skillset, but if you have the means there is nothing preventing you from generating and using your own key.
Honestly it seems like a good basic security precaution, not only to prevent against leaks like this, but also to counteract any backdoors (although kind of a moot point with chipmakers).
In many BIOSes were you can apparently remove all keys and the firmware still loads its own builtin components, that's because the manufacturer has put a backdoor so that their own components can always be loaded irregardless of Secure Boot state. (Otherwise users would be able to brick their own machines). MSI, for example, does this. And guess what: with these leaked keys, now anyone can claim to be a "manufacturer's own component". Secure Boot is useless.
You are going to tweak them again, and check down the line (ex: grub) that they match the hash you've stored, say inside you secureboot, or in your TPM
This should get you MORE security: before, you had to accept whatever the board manufacturer though it was ok (ex: any WWAN or WLAN cared with just these Ids). Now you can add more checks (just this serial or mac address) and refuse to boot.
Someone could do the same, but if you verify at the next level (ex: grub, etc) that you tweaks are present, you can refuse to boot if they aren't.