There’s a big difference between accepting people will post links that just happen to, sometimes get people past paywalls - and operationalising that so it’s the default behaviour
Actually I'd say the opposite: If it only happens with paywalled sites it's clear that its purpose it to circumvent paywalls. If you always do it, It's so there is a record of the original site at time of posting.
It would also help with sites that can't handle the hacker News traffic load. Happens all the time