There are lots of other places where I can get non-bitcoin content.

Yep, my feelings.

If anything one could have L1 vs L2 subs, a mining sub, a markets sub (trading, exchanges, etc), maybe a privacy sub, etc

I agree, only I suspect there isn't enough of this sort of Bitcoin-related news to break it up yet.

a random/OT sub could test value-for-value in a broader market, in a certain sense.

I don't think we need to do that yet. Even with an OT sub it would probably still mostly be bitcoiners in there.