Check out !worldnews@lemmit.online. The admin of lemmit.online has set up a bot that fetches reddit posts via RSS, making it much easier to make the switch and of course not getting any ads.
You can make requests for subs to fetch at !requests@lemmit.online.
In the end we’re just using lemmy and lemmit’s bot as a simple RSS reader, so nothing illegal or even remotely unethical happening here.
Probably would work to seed small communities with subreddit data, but…the maxim of “the real LPT is always in the comments” holds true (i.e. posts without comments is not what these places are about) and until users come and interact, this isn’t a substitute for being a real community.
Def a decent idea to jumpstart communities, as long as people aren’t too put off by the post data coming from reddit.