Sure. Maybe our approach is just different. I truly believe if the link is external it is much polite to forward user’s browser to separate tab. That prevents them from interrupting the experience they have/had while being at Forum pages.
Our forum is highly active, not sure it’s okay for a user to be interrupted by leaving the website altogether by following the link. The link leads to our Telegram channel, if this is the case.
In the end, I do not propose making external links open _blank by default. I suggest you give Discourse admins an ability to control how any links open from this specific component/configuration feature