Google Cloud customers had their servers patched a month before the vulnerability was publicly announced. Your customers got the patch whenever your Linux distro pushed out the microcode update. But this doesn't mean that Azure and AWS also had to wait, I would expect Intel to provide the update to them some time before making it public.

Also, how many vulnerabilities relevant to public clouds does Google detect in one year, and does that outweigh the lack of support and care you can expect from Google?