Possibly. But, if you claimed him as a dependent on your own return, he would not qualify to receive the second stimulus.
Since the IRS did not begin accepting returns until Friday, February 12, 2021, it may just be a few more days before his return is accepted.
If he submitted the return and later did receive the second stimulus check, his return will need to be amended(changed).
For more details, see: Questions and Answers about the Second Economic Impact Payment: Eligibility
