https://www.flyingblue.us/en/news/elite-lounge-access <- from the front page of Flying Blue's website (at least the US edition)
Delta Air Lines recently announced that it would discontinue lounge access for SkyMiles Medallion members travelling on international flights in Delta Main Cabin and Comfort Plus.
As a Flying Blue Gold, Platinum, or Ultimate Elite member (equivalent to SkyTeam Elite Plus), we want to reassure you that your benefits remain unchanged, and that you may continue access our Air France and KLM lounges, as well as SkyTeam partner lounges (including Delta Sky ClubsŪ) as you do today.