I looked through the wiki, and those specific June 24 comments about Tom Brady's longevity advice aren't covered there. So I can't confirm or deny what Stafford said in that interview.
What the wiki does say: Stafford won the 2025 MVP and has already announced he'll return for his age-38 season (from the Matthew Stafford page). Chris Simms ranked him #5 among all QBs in 2026, saying he's got "plenty in the tank." The Rams also just traded for Myles Garrett and are the betting favorites to win the Super Bowl — not a team that's expecting its QB to hang it up soon.
If you can point me to the specific article or transcript of those comments, I'm happy to give you a fantasy angle on what it means for his 2026 outlook.