I’ve never tried to sell anything on Reverb, I tend to use eBay when they’ve got the old 70% off selling fees or I sell on here. I’ve bought a couple of things off Reverb though.
My wife got a warning off eBay for selling something outside the site, but it was pretty friendly and basically just highlighted the policy to her and asked her not to do it again or her account would be suspended for a month of whatever.
The important thing was that they made the policy very clear, both in terms of their expectations and their ability to monitor behaviour.
It sounds like the biggest problem here isn’t the policy, or Reverb reading messages, it’s that people probably aren’t reading the terms and conditions and then reverb aren’t being particularly professional about dealing with breaches of those terms and conditions when they occur.
How much does it hurt to give people a friendly reminder of the rules before going nuclear on them?
I think if Reverb and eBay want to remain relevant, they need to prioritize dealing with the scammers, partly by offering more help and advice to buyers and sellers about how to protect themselves, but mostly by actually dealing with the fucking scammers that are everywhere on both sites.