Yes and no... It's really important that this be viewed from the context of the discussion opened by theo in the video from the previous HN post (provided in this thread by codewriter23).
Here's My TL;DW from the irritatingly poor quality video:
Yes, they are pissed that they are being excluded (rumour is amazon and google have been implementing fixes).
However, they are not necessarily "not-respecting" the embargo according to the proposed methodology Theo outlines in the video: to (speculatively) exclude _any_ potential source of speculative execution vulnerabilities to ensure they are safe without giving weight to any one rumour. And then gradually prune back the precautions as they become publicly disclosed.
Apparently they used a similar strategy previously to provide patches for sshd before they were allowed to publicly disclose the vulnerability... prevent the bug from being reachable without revealing exactly what is broken in the commits by never touching the offending code. In this case the idea is to be non-specific, disable a whole class of things even though it might not be necessary (because in this case they really don't know where the problem is exactly).
Disclaimer: The above is not my opinion, it was my interpretation of the relevant context from the video, i do not know if it matches their actions.
It seems possible the commenter on the oss-security mailing list is not aware of this strategy and is giving more weight to openBSD's patch than it deserves (and perhaps wrongly implying openBSD have disrespected the embargo as a sideffect).
However these patches are way beyond me so I cannot tell.