I don't like the idea. It seems like those fake websites that scrape stackoverflow and SEO to ruin Google search. Avoiding those sites are among the reasons people type "reddit" into searches. People want authentic interactions and I think mirroring reddit into Fediverse lacks authenticity and undermines its authenticity. Content here should be from people who are here.
If someone wants to assimilate content from reddit into something new and post it here that's good. That means the person is here and can be interacted with.
If someone wants to repost their own content here, that's also fine. They are here to interact with.
I just really think it's a bad idea to deliberately build a ghost town and think people will move in.