how likely is he to make it?
He's only been called up into the preliminary 30-man squad, with two other keepers, one of whom is Trevor Doornbusch who is extremely promising and likely to start.
They will cut a keeper when they release the final two-goalkeeper squad, a good chance it'll be Woud left home as he's the least established. Even if he does make it he'll likely be on the bench, so not a huge risk for us as it stands right now.
He has to apply to Fifa to change from New Zealand to the Netherlands, so that will be the crucial point here, not whether he takes the field.
My reading of it is that even if FIFA approve his switching to play for the Netherlands, Woud won't be allowed to play for them in the FIFA u-20 World Cup Finals due to Article 8 b. of the Regulations Governing the Applications of Statutes, FIFA Statutes:
"b) He is not permitted to play for his new association in any competition in which he has already played for his previous association."
Woud played for NZ at the u-20 World Cup last year, so he won't be able to represent Holland at the same event.
He may be able to play in friendlies and UEFA u-19 qualifiers though.