Did the transfer of ALL content from one iMac to another work as expected, from this article?

Did you follow the steps, at > Move your content to a new Mac - Apple Support

It always has of me for the contents of the Time Machine backups. I've done it maybe 20 times over the last couple of years ... family and friends.

But TM does not replicate the OS onto the TM backup drive so not all is transferred to a new or different Mac.