i think what they are talking about is to provide technical means for the xanadu features, while leaving the legal questions to others.

so i suppose that mimix will support transclusion, but it's up to the user to figure out whether transcluding a certain document is a copyright violation or not.

interestingly, iframes in html are an example of transclusion, so this is not exactly a new feature, and there are discussions on copyright about it:

https://www.plagiarismtoday.com/2009/04/07/is-the-diggbar-co...

https://policyreview.info/articles/news/eu-ruling-embedding-...

(funny how that seemingly contradicts the link-tax which started this branch of the discussion. i can transclude but i have to pay for a link?)