Well sure, you'd get the cert revocation updates, but you wouldn't get security fixes, which seems equally Bad. Why wouldn't you just let Chrome do what Chrome does? What would you gain by actively borking its update process?
There are plenty of good reasons to "bork its update process", for example if you work in enterprise and have a change management process for browser updates. Or if Chrome introduced a feature you don't like (like Lion fullscreen). Or if you prefer to use your OS's package management system for browser updates.
It's not so much a matter of Chrome's update process as your update process. If that's "I want the newest version as soon as it comes out, all the time", then great, but there's no guarantee that's true. That's the exact reason Firefox is doing its whole ESR thing.
And since you're bringing software updates into this, even though an optimal strategy will target both problems independently: one can't force users to restart without a lot of pain, as long as there isn't true session checkpointing.
[0] Thialfi: http://research.google.com/pubs/archive/37474.pdf
By "Chrome will instead rely on its automatic update mechanism" it means there will be a separate update stream using the same system, not that revocation list updates will be packaged with new Chrome versions. The latter would mean that not upgrading Chrome would stop you from getting cert revocation updates, which would be a Bad Thing.
To quote the original blog post[1]:
"Our current method of revoking certificates in response to major incidents is to push a software update. Microsoft, Opera and Firefox also push software updates for serious incidents rather than rely on online revocation checks. But our software updates require that users restart their browser before they take effect, so we would like a lighter weight method of revoking certificates.
"So Chrome will start to reuse its existing update mechanism to maintain a list of revoked certificates, as first proposed to the CA/Browser Forum by Chris Bailey and Kirk Hall of AffirmTrust last April. This list can take effect without having to restart the browser."
[1] http://www.imperialviolet.org/2012/02/05/crlsets.html