I looked through the wiki and expert takes, but I couldn't find any quote from George Kittle about NFL stadiums swapping turf for grass ahead of the 2026 World Cup. That topic doesn't appear in the wiki's coverage.
If you'd like, I can tell you about what is in the wiki about Kittle — like his Achilles recovery timeline, his 2026 fantasy outlook, or his thoughts on the 49ers' trip to Melbourne for the Week 1 game in Australia. But on the turf-vs-grass World Cup question, the wiki doesn't have anything from him.