No. Derivative status is available to a spouse and unmarried children under twenty-one, so a twenty-two-year-old is outside it regardless of dependency, schooling or living at home. The sixteen-year-old can be included, subject to how long the process takes and the age calculation that applies.
Give the older child a plan of their own
This is a common and painful discovery, and it is better made at the outset. An adult child over the limit is not part of the family's petition and needs an independent basis to live in the United States: a student route if they will study, an employment category if they qualify, or a family-based route later if a parent becomes a permanent resident and sponsors them, which has its own long timeline. Discuss it openly before the family commits, because a plan that separates a family is a different decision than the one people think they are making. For the younger child, watch the calendar: the age question depends on dates the family does not control, and delays in gathering documents are within their control.
Hypothetical example: a cultured-seafood investor has an unmarried twenty-year-old son who may marry before visa processing finishes. A first review records his birth date, marital status, and the relevant filing and visa-availability dates, then obtains advice on his derivative position. Marriage can alter eligibility, and age protection depends on statutory timing rather than family intention. EB-5 leads first to conditional permanent residence, so the family should also plan for the later condition-removal stage. Do not promise an adult child inclusion until the dates and facts have been tested.