On the 2022 Interrail map (found on this page), some lines around Barcelona run by FGC are shown as "Railways with discount”. It refers to the pass benefits section in the rail planner app for details, but it has no mention of these rail services. I also checked the benefits portal but nothing there either (interestingly, the website lists 26 benefits for Spain, the app 25).
The FGC website does not mention Interrail or Eurail anywhere.
So is this still accurate? I have also asked FGC via their Facebook page.