Also, CPU design changes take a long time. 6 months may seem a long time from the perspective of HackerNews node.js type hackers, but it's a bit harder to patch decades worth of CPU microcode than a website.
also look at the exploit numbering:
Variant 1: bounds check bypass (CVE-2017-5753) Variant 2: branch target injection (CVE-2017-5715) Variant 3: rogue data cache load (CVE-2017-5754)
according to https://cve.mitre.org/cve/identifiers/ this is sequence based so `Variant 2` was recorded to CVE before v1 and v3.
I get it may take a long time (that is fine even if the patches took a few more days), what I don't get is that they released it to production (server) envs seemingly without testing. Surely even rudimentary testing (deploying on a few 1000 different server platforms for a few hours at least should be something that Intel does for all microcode updates, after all they are rather more important than js Node packages as you point out)