I know it would be technically feasible, but would it be fully legal for Lemmy to scrape and re-populate posts from all of Reddit's niche community subreddits (and threads and conversations), 1:1, even maintaining the original user names associated with them... but not connecting them to actual accounts? Almost like static content. And they could use that as a basis for the new community, so that there is at least a baseline repo of content to peruse as real members start to join and post new topics/content?

I feel like that's a nice unorthodox way of making it not feel so viscerally "new and empty", which is usually what leads to a kind of inexplicable ick factor most people have when evaluating whether or not to join a community.