Partly. Under the Child Status Protection Act the time the petition is pending is subtracted from his age when a visa becomes available, provided he seeks it within a year; whether the result is under 21 depends on the real dates.
Subtract the pending period from the age at visa availability, then check the result
A derivative child of an EB-5 investor must be unmarried and under 21, and the Child Status Protection Act provides a specific calculation. Take the Torbay son's age on the date an immigrant visa becomes available to the family under the Visa Bulletin chart that USCIS designates for that month, subtract the number of days the EB-5 petition was pending, and if the result is under 21 and he applies for the visa within one year of availability, he qualifies. A son who is 20 at filing, with a petition pending eighteen months and a visa available at approval, has a CSPA age of 20 and is protected.
If the category is backlogged so that availability comes years later, the subtraction may not be enough. The dentist should bring the exact birth date and the current bulletin to the consultation rather than assume. A son who ages out needs his own route, such as student status, and cannot be added later as a derivative.