The article does not say that. It conflates copyright and trademarks a couple of places, but it's clear that this is a combination of Redbubble applying their own over-cautious policies combined with trademark registrations, not copyright.
There are plenty of issues with trademarks too, but they are very different to copyright.
I think the nub of the article is that the artist had his artwork banned just for referring to the fact his designs were inspired by a mediaeval manuscript ie. 'The Book of Kells' because Trinity College have trademarked 'The Book of Kells' to use as a brand name on products they sell.
As it says in the article
>...So, are [Trinity College] actually saying that no one is even allowed to mention "The Book of Kells", for fear of violating their copyright? If so, that’s really going to fuck up a lot of History books!...
I take on board what you mean about the distinction between Copyright and Trademark, but I think it still serves to illustrate just how ridiculous the legal minefield around both issues has become.
There are plenty of issues with trademarks too, but they are very different to copyright.