Is it OK to restore master db backup, after changing WSFC clustered instance into non-clustered instance
To make sure I called up the Microsoft support and they said this might work, but not supported. They suggested not to do it. According to the support guy there are some difference in system databases when clustered or not, and the difference can cause an error, and there are known such cases too.
And they gave me this link.
So the answer seems to be no.