FDJ has signed a 6-year extension with lower wages two months after the 2-8 loss when he already knew what situation we're in. Surely, he probably didn't expect Messi to leave but I think he was aware there might be some tough years ahead of us.
I don't believe he's thinking about leaving now. Will surely also stay around if Laporta would appoint Ten Hag next year (not saying he should but there were rumours he's his prefered candidate to replace Koeman; would probably be an improvement but I have my doubts about him as well). Now if we'll still be highly uncompetitive against teams like Bayern in 2023 or so then I could see Frenkie starting to think about leaving.
But there is still a big difference between players starting to think about leaving and being internally quietly unhappy to publicly demanding to leave and actually be sold. Clubs have kept want-away players before. We usually don't (and we actually have the opposite problem in recent years that players we'd want to offload don't want to leave
) which I think it's the right decision. It's better to have money to bring players that want to play for the club than keep those who don't want anymore. But in Frenkie's case even in 2023 he'd still have 3 years left on his contract. He's a true professional and would still give his best even if he wouldn't be totally happy to stay imo so it would be fully up to the club (and what offers we'd get) to decide if (and when) they want to sell or not. Which would also depend on how important they'd believe he still is to the team at that point and how close we're to become consistently competitive against top teams again.