Refiling for Relocation after Refusal: If relocation is refused once, does that mean that the custodial parent's dreams of relocating with the child are crushed forever?

No, all issues related to children like custody and relocation are dynamic, and can always be re-opened. Relocation may not be in a child's best interests at a particular time, but may be later on. A custodial parent who is refused permission by the court to relocate when the child is young may be successful later.
Abduction From Israel