The dataset from ArchiveTeam is quite extensive, and since most posts have media that are hosted on external services, it shouldn’t put too large of a storage burden on Lemmy NSFW.
There was a discussion about this (specifically a reposting bot) and it’s pretty split between allow, disallow and allow only in certain subs. There are definitely a lot of communities here that are empty or nearly so, but I think most would rather see organic growth instead of automated reddit-cloning.
I have used reddit archives as one of the sources to find content to kickstart communities, but I assume you’re talking about something in bulk that’s a lot more automated.
You could try and convince the moderators of your favorite protesting NSFW subreddits to move over here. (Reddit mirror of the list)
For kickstarting I personally just dumped the relevant ones from my own stash (that were still up, I have a few more I’ll need to reupload because Imgur & co) and let the community take over from there, though of the 3 communities I tried it only seems to have worked for 1, so YMMV.
