Check out google, facebook, phpBB any any similar websites, they all do open external links in new tab.
I know I can use middle click, (laptop and mobile users btw often cant do it easly – usually right click > new tab that is not good ux).
But anyway fact is that many times I’ve lost tab with envato during some link to link travel from this forum.
Any external website not connected with actual should open in new tab. I dont even feel need to explain this.
And btw in my opinion items previews should not open in new tab. It was annoying, usually when browsing multiple items.
I’d be horribly irritated if forum links opened in a new window on my phone
You’ll have to explain why forcing me into a new window is a good user experience, because it’s not. It’s an outdated practice