It would be relatively straightforward to do automatically. Both OS's use a Linux kernel and Linux filesystems. Whether they will or should is a different question, but technically it's straightforward.
And what do you think the probability is that Google makes it a completely seamless update? I'd put it at well under 1% personally.
And what do you think the probability is that Google makes it a completely seamless update? I'd put it at well under 1% personally.