Based upon absolutely nothing I reckon Visma will have a spot for Ruud Junior Nagengast and/or Jurgen Zomermaand. They will have to protect the Dutch image in some way.Gotta wonder, is Dutch cycling dead? Like will Visma even have any Dutch young riders in their devo team in the future? Ofcourse there's a few, but they are at Alpecin (Del Grosso, Remijn for example) and there's still DSM but I feel like the Netherlands have a problem with development right now.
However, to your point, you are correct. There will always be an influx of some talent since everybody (in the most literal sense of the word) owns a bike here and they'd discover they got some talent for it. Nevertheless, those that do make it probably do so because they have a surplus of talent (or choose to go to Belgium), and not because of some developmental structure. I think this is best shown with the women, where the sport is only kicking off and actual structures or ideas don't matter much. Now that women cycling is actually getting serious, sooner or later other countries will catch up, and then you become reliant on actual development, of which there is very little.
Organising races and such on Dutch turf even on pro level is close to impossible nowadays, actual hellscape. National legislation says there needs to be an X amount of qualified security. If you can hardly get enough crew to organise a pro race, how difficult must it be to gather for something as uninteresting as youth racing? Renewi Tour is basically Belgium Tour 2.0 because of this. Local government do not help much either, because they all seem more interested in securing grand departs to boost the local economy and image, rather than investing in actual sports.