They can, because their citizenship counts toward the fifty percent ownership threshold whether or not they intend to move. A shareholder holding U.S. permanent residence is generally not counted as a treaty national, and that is true regardless of where they live.
Every shareholder is part of the analysis, movers or not
Families often assume that only the people relocating are relevant, and that is not how the ownership test works. A sibling with a green card, a parent who took U.S. residence in retirement, or shares held by a spouse who is a citizen of a third country all affect the arithmetic.
The remedy, where one is needed, is usually corporate rather than immigration: a restructuring agreed among the family before the acquisition. That is a conversation better had early and calmly than under deadline. Separately, for the family members who do move, a spouse accompanying an E-2 principal is employment-authorized incident to status under current policy, while children may study and never work, and dependent status ends at twenty-one.
Hypothetical example: Imani is starting a dance-apparel manufacturer while her spouse wants to pursue a separate career. A family assessment should list each person’s nationality, passport validity, relationship evidence, school needs and employment plan. The investor’s treaty nationality and ownership documents establish the principal route; marriage and birth records settle derivative relationships.
Discuss the spouse’s work plans before filing, because an eligible E spouse may work incident to status whereas a child does not receive that employment permission. The mistake is treating all dependants as interchangeable. Sequence travel only after the investor’s business role and funding record are coherent, then prepare each family member’s own application materials.