Timbo isn't anywhere near De Ligt or De Jongs level. De Jong wasn't even at Ajax until he was 18 - he was at Willem II. De Ligt broke through at 16 and you can bet if we'd offered a decent fee theres no way Ajax would of turned it down.
there's no way De Ligt would have been let go or wanted to leave at 16 regardless of the fee. There's a reason he broke through at 16. everyone in and around the club knew they had gold in hands with him since he was like 14. He's a die-hard Ajax fan who was a season ticket with his dad his whole life. he was at the club from the age of 8 or something. he had plenty of offers, I think from like Bayern and stuff at 15, but there's no way he was ever going to choose that move. Just like Monaco wouldn't let Mbappe go for a seemingly ridiculous offer just before his breakthrough, knowing how he'd be valued in the very nar-future, neither would Ajax with De Ligt. The whole club/first team depends on players like De Ligt breaking through and leading the first team. There''s no way we can get equivalent talent externally. There's no way any other team could have signed De Ligt at 16 regardless of the offer. Fosu-Mensah and Dilrosun left because they were the generation when Ajax made a policy change of holding off contract offers until players were 17 to sort of "test" their willingness and commitment to the club and development and it backfired with all three biggest talents (Peeters as well) leaving immediately for United, City, and Real Madrid. A similar story then happened the next year with Malen (/Raiola) to Arsenal and the club quickly changed it's contract policy back, though still losing Redan and Castillo to Chelsea. De Ligt had plenthy offers to leave for every top club in Europe at that age, just like all of our good talents do. I don't know why that scout thinks United would have had a chance regardless of the higher-ups.
with De Jong it's different. If he's talking about when he was still at Willem 2, you'd have had a chance. But then PSV and Ajax had a very public fight over signing him. He chose Ajax and the trajectory that goes along with it. He was immediately very highly rated by the club and again you very very probably wouldn't have got him wanting to leave or Ajax willing to let him go, though I think for crazy money it would have been possible, unlike with De Ligt.
Also TFM was very similarly rated to De Ligt when at Ajax. Had all the ingredients to be amazing. Don't know how the decision was ever made to try to make him a rightback so late in his development.
One thing you do see btw is that certain players tend to make the move partly because of their parents' financial situations. An example of that is TFM who, from what I read at the time, had a family that could really use the guaranteed income that a United contract brought them