In the MCO today, we always reboot during initial node bootstrap pivot. This is because machine-config crd also manages non-ignition field like OSImageURL, kernelArguments, extensions, etc. Any update in thse fields would require node reboot.
Most of the time cluster OSImageURL is different than bootimage and hence it results in node reboot.

However, there are certain usecases (like baremetal) where we would like to skip this reboot to bring up node faster.  The cluster admin would boot the node with bootimage matching matching with cluster OSImageURL  but it will still lead to reboot.

For this effort, two area has been identified where it is possible that MCO can be improved to skip reboot during initial pivot:

1. Bootimage matches cluster OSImageURL
2. kernelArgs supplied to MachineConfig can be applied during node provisioning

Related RFE - https://issues.redhat.com/browse/RFE-3621

Note: With additional findings from Assisted installer team, scope of work has been re-framed to meet the requirement of assisted installer workflow.