If anything, shouldn’t it be encouraged, and even automated? I’m including even the ‘old’ stuff from reddit here. Reddit shouldn’t be the absolute owner of the content submitted by users. When I migrated here, it wasn’t because of me being against reddit users, but being against reddit the company. Copying the content here actually hurts the company in sense that they don’t get to then gatekeep the crowdsourced content.
I’ve seen a number of communities that are otherwise dead without Reddit reposts, and being the most subscribed community for a given topic with the latest post being months ago is definitely not going to attract new users.
It’s either don’t repost, and new users won’t join because of dead community, or repost and have some activity, and maybe new users will join. With dead communities, new users won’t magically join, and new content won’t magically get created.
One such example was the bcpcsalescanada community, which was revived due to reposts.
This is unfortunately part of migrating. Not all communities can just move over. Larger ones will develop and with that side communities will start with a large enough user base. Reposting in this case still doesn’t do anything other than give you the exact same content as Reddit just now it’s without an interactive user base.