You do not have to claim him, but if he ''can'' be claimed, he is still considered a student dependent for tax purposes and would not be eligible to claim EIC. You ''can'' claim him if he was a full-time student for any 5 months of 2021. See the definition below.
Claiming EITC without a child
IRS - EIC ITA interview
A full-time student is a student who is enrolled for the number of hours or courses that the school considers to be full-time attendance. If he does not qualify as a full-time student in 2021, you can not claim him and he would be eligible for the EITC.
To qualify as a student, the person must be, during some part of each of any five calendar months of the year:
- A full-time student at a school that has a regular teaching staff, course of study, and a regularly enrolled student body at the school, or
- A student taking a full-time, on-farm training course given by a school described in (1), or by a state, county, or local government agency.
The five calendar months do not have to be consecutive.