> Just from a cultural homogenization point of view, it's been a negative.

You're not wrong, and so I think the future of this is meant to be opt-in rather than opt-out. Realistically what a two-way opt-in looks like would be:

1. A topic is created
2. A cross-post request comes in
3. OP (or mod) approves or rejects
4. Topic is cross-posted.

However that in general introduces a significant amount of overhead and mental burden that would disincentivise usage of cross-posting.

I'm not sure what the answer is.

I used to be very bullish on the idea that cross-posting would solve so many problems via inteconnection, but there are some very significant social concerns that would absolutely taint the very idea.

So, we tread carefully.