If this is as described, it's a pretty major failure of security-vulnerability report triage, and rises to the level where security departments at major corporations will be having meetings about whether they want to ban AMD hardware from their organizations entirely, or only ban the AMD update application. If this had gone the "brand name and a scored CVE" route, it would probably have gotten a news cycle. It might still get a news cycle.

The threat model here is that compromised or malicious wifi hotspots (and ISPs) exist that will monitor all unencrypted traffic, look for anything being downloaded that's an executable, and inject malware into it. That would compromise a machine that ran this updater even if the malware wasn't specifically looking for this AMD driver vulnerability, and would have already compromised a lot of laptops in the past.