Some clarifications:
Firstly, the "backups" are not backups but naive scrapes. They were taken due to the WebNX fire that took out the EEVblog forum for a while. We figured that it was a good method of preserving content which was generated should the worst happen one day. Everything is ephemeral on the Internet.
Secondarily, transferring content, caching and archiving it is not a copyright issue. If it was it would be illegal to use web browsers and archive.org, google and Microsoft would have been sued off the Internet ages ago. A couple of people tried this on in the early 2000's and looked like wallies. Broke wallies.
Thirdly, there is no copyright issue with reproducing the content elsewhere. While EEVblog asserts rights to the content posted, that does not mean the authors do not retain rights to it as well. In fact I will be reproducing some of the content I have posted here on my web site which I am 100% entitled to do. It will not be verbatim of course as it's a more formal medium but I could legally reproduce it anywhere I like.
Fourthly, the only place any copyright can be asserted is in court and if anyone went to court over this they'd be a wally.
But with those facts on the table, yes it doesn't make sense to reproduce it unless for some reason it disappeared. It has a negative SEO impact for both sites and doesn't really help with assigning what is where. That is originally why I suggested freezing the thread and continuing on groups.io only. For the sake of both EEVblog and TEA SEO stats only and the possibility that duplication hurts both sets of people.
(some) people think this is emotionally charged but it's all logical at the end of the day